Medical Issues

Medical issues can be a big problem in donor-conceived populations, especially when there is no regulation regarding the number of offspring and no universal standards for updating medical information. Report all births to your sperm bank/clinic!

Reported Issues
Medical Update Statistics
Genetic and Medical Illnesses and Disorders



The following news articles are stories of medical issues in donor families.



May 2020: NBC Affiliate 11Alive News: GA Supreme Court Justices get heated in sperm bank case. A Georgia sperm bank claims no accountability for selling sperm of man with a criminal history and a diagnosis of bi-polar with schizo-effective disorder.



September 2019: The Washington Post: The children of Donor H898. "The boys are part of an autism cluster involving at least a dozen children scattered across the United States, Canada, and Europe, all conceived with sperm from the same donor. Many of the children have secondary diagnoses of ADHD, dyslexia, mood disorders, epilepsy, and other developmental and learning disabilities." CBS Chicago: Single Sperm Donor Linked To Numerous Children With Autism, Other Disabilities.

February 2019: Riverfront Times: St. Louis Dad Sues Sperm Bank After Baby Is Born With Genetic Disorder. "Thalassemia is an inherited blood disorder that in severe cases requires a lifetime of blood transfusions. It was never supposed to show up in the baby that a St. Louis couple conceived in 2015 using donor sperm. That's because the donor had been screened for just that genetic disease — or at least, that's what the paperwork from the Manhattan Cryobank had stated."



September 2018: The Daily Mail: Is everything you thought you knew about parenting wrong? Top geneticist claims he can prove a child's character is fixed at birth and grasping this secret can make you a better parent than ever. A great article about nature and nurture and what makes us who we are: " of the country’s top psychologists and behavioural geneticists, Professor Robert Plomin, of King’s College London, offers an emphatic conclusion. It is drawn from 45 years of research and hundreds of studies. He says the single most important factor in each and every one of us — the very essence of our individuality — is our genetic make-up, our DNA. The basic building blocks of life that we inherit from our parents are what determine who we are — not how much they loved us, read us books or which school they sent us to. DNA accounts for at least half the variance in people’s psychological traits, much more than any other single factor. Put simply, ‘nature’ trumps ‘nurture’ every time, and not just marginally, but by a long, long chalk. Our DNA, fixed and unchangeable, determines whether we have a predisposition not just to physical traits — from how tall we are to how much we weigh — but also to our intelligence and our psychology, from a tendency to depression to having resilience and grit."

June 2018: BioNews: Genome study finds shared genes in psychiatric disorders. "Several distinct groups of disorders with genetic links emerged in the study. The highest degree of correlation was between schizophrenia, depression, ADHD and bipolar disorder. At the same time, there was significant overlap between anorexia nervosa, obsessive-compulsive disorder (OCD) and schizophrenia. In addition, the study found that depression and Tourette's syndrome had genetic links, as did autism spectrum disorder and schizophrenia."



November 2017: TIME Magazine: 2 Couples Sue After Children Are Born With Genetic Abnormality Traced Back to Donated Eggs. Washington Times: Couples sue fertility clinic over eggs with genetic defect.

October 2017: Sperm bank settles negligence lawsuits. Xytex will never have to answer questions in court regarding its decision to sell the sperm of a donor the company would later learn had a criminal record and severe mental health problems.

May 2017: A Lawyer's Perspective on Genetic Screening Performed by Cryobanks

March 2017: Huffington Post: Sperm/Egg Donation: Genetic & Mental Illness

March 2017: NBC Atlanta: Child diagnosed with cancer denied access to medical history

February 2017: NBC Colorado: Mother worries about sperm donor's medical history

February 2017: NBC Atlanta: Sperm for sale: Fighting for change



November 2016: Cook County Record: Woman says defective semen [sperm] caused autism

August 2016: Prolific Sperm Donor Was a Schizophrenic, Not a Neuroscientist, Leading to Spate of Suits

April 2016: What's missing from current methods for genetic screening of sperm donors? "To protect future children from highly heritable diseases, sperm banks need to modernize their testing methods..."



December 2015: EC Gynaecology Commentary: The Need For Comprehensive Genetic Testing of Gamete Donors

December 2015: Huffington Post: The New "Check Box" That Needs to Be On Pediatrician's Forms

September 2015: Huffington Post: Donor Conceived People and The Reproductive Medicine Industry Disconnect

April 2015: Couple sues Georgia sperm bank, claims donor wasn’t as advertised. "A Canadian couple is suing a Georgia sperm bank [Xytex], alleging that the donor the company provided for them is a schizophrenic with a criminal past whose photo was doctored to make him look more attractive."

April 2015: The Toronto Star: Sperm donor shortage forces Canadians to look to U.S.

April 2015: U.S. sperm bank admits it doesn’t verify donor information

March 2015: BioNews: UK twin study shows autism 'largely genetic.' "A UK twin study estimates that between 56 and 95 percent of autism spectrum disorder (ASD) cases are attributable to genetics. The findings, published in JAMA Psychiatry, suggest that the risk of ASD and related traits is more strongly influenced by genetics than previously thought. 'These results further demonstrate the importance of genetic effects on ASD, despite the dramatic increase in the prevalence of the disorder over the last 20 years,' explained study author Beata Tick from the Kings College London team."



December 2014: USC Center for Health Journalism: Code Unknown: Trying to connect with sperm donor through online community. A donor family deals with long QT syndrome (can lead to sudden arrhythmia death syndrome or SADS) in two generations.

April 2014: Fox News: It's time for states to outlaw anonymous sperm, ova donations

February 2014: BioNews: Out-of-court settlement for girl conceived with abnormal donor sperm. A London fertility clinic has settled a claim over a 4-year-old girl born with the genetic defect balanced reciprocal chromosomal translocation, after a mix up in the sperm used in her conception.

June 2013: Flanders News: Danish sperm donor also passed on genetic disorder in Belgium. Nordisck Cryobank's donor 7042 has passed along the rare NF1 genetic disorder to offspring. Of the 43 children in 10 countries conceived with the help of the defective sperm, 9 have the disease (also known as Von Recklinghausen's disease), and 2 of those are in Belgium. NF1 is a rare genetic disorder affecting neurologic functions in humans.

May 2014: Dear mister President of the United States of America (Letter to President Obama from a Belgian woman). A plea for "better and mutual regulation, control and guidance of parents, donors and donor conceived offspring," specifically mentioning the case of Nordic Cryobank/California Cryobank donor 7042, who has the genetic disease NF1 (neurofibromatosis) and whose currently known offspring (at the time) number "a staggering 99 children worldwide, of which 34 [were] conceived in [the U.S.]."



May 2013: NYU Interventional: Donor children live in ignorance of their father's illness. Cryos in Denmark has been criticized by the National Board of Health for not adhering to the recommendation of 25 pregnancies per donor when it was discovered that 64 children may have inherited a rare disorder from their biological father, Donor 45.

March 2013: Copenhagen Post: Sperm donor with genetic illness speaks out. The Danish government health agency has been criticized for not looking for children who may have been born with a cancer-causing illness, Lynch Syndrome, inherited from an anonymous sperm donor. Even though the mortality rate can be significantly reduced with early treatment and diagnosis, the health authorities have decided not to search for the five to ten children who may have inherited the disease.

January 2013: Readers Digest: Can you Inherit your Mother's Health? Many aspects of our health are genetically linked. According to researchers from the Institute of Cancer Research at the University of London, there's a 57 percent chance that a girl will start menstruating within three months of the date that her [biological] mother began. Here are 9 other women’s health conditions that experts say we may have inherited from our [biological] mothers..."



November 2012: America Now: Rolling genetic dice with a donor. Some ART facilities screen for some diseases, but few screen for potential genetically inherited conditions. This article talks about the repercussions when thorough screening hasn’t happened, and gives a synopsis of a few other articles on the same topic.

September 2012: BBC News: Denmark tightens sperm donor law after NF1 transmissions. Due to a sperm donor passing along NF1, a rare genetic condition that affects the nervous system (and is untreatable), Denmark has passed new restrictions on Danish sperm bank operations, including limiting the number of offspring to 12 per donor.

September 2012: Daily Mail: Danish sperm donor passes rare genetic disorder to at least five of the 43 babies he is thought to have fathered in ten countries. The two September 2012 articles are referencing an earlier story (see the May and June 2011 articles below). The interesting thing about this story is that this donor is also a California Cryobank donor. We regularly hear stories about sperm donors passing along medical and genetic issues to children here in the US, but no regulation is ever initiated.

May 2012: The New York Times: In Sperm Banks, a Matrix of Untested Genetic Disease. The case of a child with cystic fibrosis, which was genetically linked to the donor used to conceive him, highlights the need for more regulation of the sperm bank industry, specifically around the genetic testing of sperm by cryobanks. In this case, the sperm had been purchased from New England Cryogenic Center (NECC) who had purchased it from a bank that is no longer in business, and was at least 20 years old.

February 2012: CBS: Parents Sue Cryogenic Center Over Child’s Cystic Fibrosis. This CBS report of the lawsuit brought against New England Cryogenic Center exposes that the sperm bank has faced very little oversight in its 30-year history. It also points out that New York will not allow sale of NECC’s sperm donated at and purchased from another defunct cryobank. It is reported that NECC in initiated internal regulations surrounding that restriction, but did not remove that donor from their catalog.



July 2011: Sperm Donor's 24 Kids Never Told About Fatal Illness. This article addresses the question of what regulation should be in place to protect children from conditions passed along by a donor, when a donor is not required to update the sperm bank where he donated. The donor in question had surgery for Marfan’s Syndrome and an aortic defect, the same potentially fatal heart condition that he passed on to at least one of his (at least) 24 offspring, who each have a 50% chance of having contracted the disease.

June 2011: Infertility & Reproductive News: Gamete Donation: Medical and Genetic Implications. Wendy Kramer provides an overview of the medical issues that have exposed the lack of regulation of the sperm and egg donation industry, and offers recommendations for how to move forward in a more ethical way.

June 2011: The Copenhagen Post: Anonymous sperm donor passes on rare illness. A donor used in the US, Sweden, Belgium, and Denmark unknowingly passed along a genetic disease to at least nine children conceived using his sperm.

May 2011: The Local: Swedish women warned over Danish sperm. "The head of a Danish sperm bank has warned that Swedish women are 'most likely' to be among those inseminated with defective sperm donated by a man with a rare genetic disease [i.e., California Cryobank and Nordic Cryobank Donor 7042 'Ralph']."

April 2011: 2nd International Cryo Conference PowerPoint Presentation: The Case for Comprehensive Medical and Genetic Testing of Gamete Donors. This PowerPoint, presented in Valencia, Spain, describes the medical issues associated with using donated sperm and/or eggs to assist with reproduction.



August 2010: The Columbia Science and Technology Law Review: The Regulation of Genetic Aspects of Donated Reproductive Tissue — The Need for Federal Regulation. This article provides a great overview of current medical practices in sperm banks and egg clinics, noting lawsuits involving medical issues, and making a case for federal regulation.



November 2009: JAMA: Implications of Hypertrophic Cardiomyopathy Transmitted by Sperm Donation. Nine of a man’s 24 known offspring were genetically affected by his asymptomatic HCM, a genetic cardiovascular disease. At least one child has died.

November 2009: JAMA: Genetic Screening of Sperm and Oocyte Donors: Ethical and Policy Implications. This article discusses the current lack of regulation and the potential ramifications of the proposed mandate for genetic testing of sperm and egg donors.

November 2009: The Washington Times: Sperm donation testing falls short. The Washington Times reports on the JAMA study of a man who passed HCM to his offspring via sperm donation.

November 2009: BioNews: Sperm donor screening needs to be overhauled. The DSR campaigns for more rigorous testing of sperm and egg donors for genetic diseases, and advocates the use of a monitored delay in the release of donor sperm to reassure users of its safety, and to track and limit the number of offspring from each donor.

November 2009: The Washington Times: Doctor blames profit motive for sperm-donor diseases. An interview with former DSR Board of Directors Chair Kirk Maxey, discussing the lack of required testing of donated sperm.

May 2009: BioNews: The case for comprehensive medical testing of gamete donors. The DSR calls for mandatory genetic testing of egg and sperm donors.



April 2008: O Magazine: The Children of Donor X. Oprah's magazine follows the stories of several families who used the same anonymous sperm donor from California Cryobank. All of them are navigating medical issues that they attribute to genetic defects from the sperm donor.



October 2006: Fairfax Cryobank: Letter to the Editor of Self Magazine. Fairfax Cryobank responds to Self Magazine’s article “The Truth About Donor 1084.”

October 2006: Self Magazine: The Truth About Donor 1084. Self reports on Fairfax Cryobank donor 1084 and the medical issues he passed along to several offspring. The story highlights the frustration of the families, who feel the sperm bank should have been more responsive to their concerns.


Reported Issues: Health and Genetic Issues Reported to the DSR

DSR members have reported a wide variety of health and genetic issues, as well as clinics' refusal to update or share medical information. Here are some of the messages we've received.

2019 from a parent: "I was contacted by TSBC when my son was about 3, indicating 2 half-siblings had been diagnosed with Tourette’s, Tic disorder, and ASD. At the time, we were uncertain of my son's diagnosis but clearly there was something going on. Fast forward a couple of years and he was diagnosed with high functioning ASD, ADHD, and later bipolar disorder. My daughter had sensory processing disorder. We have been in contact with 3 half-siblings, two of which have mental health and neurological challenges. The one half-sibling male, one year older than my son, has the exact same diagnosis as my son."

2019 from a parent: "My son has Asperger’s, as do 4 of the 8 children we have made contact with. Worse, our donor has a genetic defect that results in aortic aneurysms and dissection. Half of his 33 living children will inherit the same. My son did; he had open heart surgery at 17. I know it is a crapshoot when you rely on a stranger’s DNA, but there needs to be tighter regulation in the sperm banking industry."

2019 from a parent: "3 of my twins' 1/2 siblings tested positive for TS (tuberous sclerosis). This was a blessing and a curse. It brought previously unknown parents into our sibling group (or parents of siblings) but it also showed all of us the dark side of donor banks. Through growing and getting to know other families, we found out that there are a few kids that were diagnosed ASD, including my twins. The myriad of emotions I went through ... like "I did not sign up for this! This is WHY I went through a cryobank to get genetic history and know health issues" etc. It turned out that the donor was a mosiac carrier for TS. I am unsure about the rest but WITH the ASD diagnosis ... my twins also have a genetic deletion. So I am wondering if there are others and the sibling parents either just don't know or are not coming forward."

2018 from a parent: "I was wondering if you could help with the following. Suppose a parent has a donor child, diagnosed with autism spectrum disorder. Then, one would find out the identity of a sperm donor (when the donor child is still young), only to discover that the donor has autism too, and apparently in a more serious way than the child (meaning, it should have been rather obvious for the donor bank when the donor offered his services). Can you hold a donor bank [California Cryobank] liable? Or are they under any legal obligation to refuse potential donors with autism? What do you need as proof, in order to start a case?"

2018 from a former sperm donor: "I received an email today from the birth mother of one of my offspring, a first! What a thrill! She chose me as a donor 25 or so years ago because I indicated that I would be open to contact. When her son was 16, he was diagnosed with MS. They learned there was a genetic link. She contacted the center and was told they were not allowed to contact me and would not give her any info. They even denied having a sperm donor program. She finally convinced them to send her the original information she had received to choose a donor. It was like a big secret they did not want her to know. I was never contacted by the clinic [Cryobiology], even though I had provided them with updated contact info over the years!"

2018 from a former egg donor: "Some fellow egg donors in a ED group admitted to lying and/or purposefully withholding information on their applications so they could be accepted. One ED even told another potential ED how many days to be off her meds so she could clear any screening done. It's not just sperm donors who cheat to make a buck. There needs to be far more accountability."

2017: "It has been proven that the siblings have a 50 percent chance of inheriting a rare medical condition from the donor. The death rate is about 20% per year and first sign of the condition is death at sleep or rest. We are looking at the period of 1978-1985 as the period of the donation for the donor. Some of the period between 1980-1983 might have been in New York State. We have been unable to get further information from the University of Florida, Shands, the donor, or from the attending physician concerning more concrete information. We know of three siblings and each carry the gene. There are also two children by one of the siblings that carry the gene."

2017: "I have a genetic blood disorder called Prothrombin Gene Mutation, thought to be passed down from my sperm donor."

2016: "I had genetic testing on my 2 boys that were conceived from the same donor. They inherited a mutation on a gene that is known to cause autism and Rhett syndrome. Both of my boys are autistic. One of their donor half-siblings who is also autistic just received genetic results and she also inherited the same mutation in the same exact spot in the genome as both my boys."

2016: "I was an egg donor over 20 years ago ... I called the office where I donated and let them know about my son having ADHD, anxety, bipolar, etc. so they could let the offspring's family know. I am assuming, because it was 100% confidential ... they really didn't seem like they were interested or were going to pass the information on."

2016: "I donated my eggs four different times at Genetics & IVF Institute in Fairfax, VA in the 90s/early 00s. Since then I discovered I carry a gene which means I'm at a much higher risk for getting several types of cancer. Since then I've tried to contact Genetics & IVF Institute so that they can relay this information to my offspring (they have a 50/50 chance of inheriting it) but they were not interested and it was obvious that they were not going to inform the families despite the fact that early screening could potentially save these children's lives. I've recently turned 42 years old and I was just told this week that I most likely have ovarian cancer (this will be confirmed through pathology after surgery) and that I will need my ovary removed ASAP. I don't know if this is because of donating my eggs when I was younger or because of my family history. It's very upsetting either way."

2016: "I have been a member of the registry since 2004. I donated eggs in 97, 98, and 99. I am concerned about the children that may have resulted from those cycles. I have been diagnosed with Autosomal Dominant Polycystic Kidney Disease (ADPKD). I have 4 children, 2 have the disease. One does not and the youngest has not yet been tested. He is 15 and conceived from the cycle in 99. I kept 3 eggs and donated 20. I contacted the clinic immediately after I found out. They completely accepted the information but did not give me any real Indication that they would relay the information. I lost my mom in 2005 to aneurysm as a result of the disease. My niece had aneurysm surgery 4 years ago. She was the youngest diagnosed with serious complications. My sisters are both in renal failure waiting for transplants."

2016: "The only way we found about a serious genetic eye condition was because we had already found a large group of donor siblings and upon joining the group, the parent of the child with the condition contacted me and told explained the condition and the importance of having my son screened no later than 3 years of age. It is a very rare but treatable condition. It turned out my son has this condition and had we not had that info my son would most likely ended up having serious vision problems due to it being caught too late. The bank we used had this information but it was not shared supposedly because only one donor sib at the time had it and there was only a 12.5% chance that other donor sibs would have it ... regardless, the info to have my son screened saved his vision and I will forever be grateful that I have the connection I have with the 12 other donor sib families!"

2016: "I am 'donor' conceived. I just found out who my bio father was. Sadly, he died 7 months ago from stage 4 renal cancer. He was only 49 years old. Also, there is some bad history of suicide and bipolar disorder in his family. I called the cryobank, Reproductive Resources in Metairie, LA. I told them his medical information and that they must immediately inform all other offspring of this information. They said they couldn't do that. What can I do? This could be a life or death situation. To withhold this information is unethical and criminal."

2015: "I am an ovum donor and I have Ehlers-Danlos Syndrome types 2 and 3, and my two children do as well. This was only discovered in my 30s. I so wish I could tell other offspring." [From the Mayo Clinic: "If you have the most common varieties of Ehlers-Danlos syndrome, there's a 50 percent chance that you'll pass on the gene to each of your children."]

2015: A mom with a very sick child who used California Cryobank: "I contacted CCB and they were adamant about not contacting the donor or providing me with information about him, going as far as saying that they discouraged contact among donor families and refusing to recommend the Donor Sibling Registry (DSR) to a donor." Read her full story here.

2015: "One of my children was diagnosed with a rare and severe type of Lymphoma/Leukemia (Precursor T-cell Lymphoma/Leukemia), which spread over his neck, throat, lungs, heart, inguinal area, blood, and bone marrow. He has been receiving intense chemotherapies."

2014: "My children have a disease called cavernous malformation disease: gene is called CCM1 (this is what all [the donor's] offspring & he should be tested for). All three who have it, have active brain bleeds, and my 8 year old has had 2 strokes, now has epilepsy from the brain damage, and one child is expected to go blind eventually. Many people live like a ticking time bomb and never know what they have with this condition so I want other families to know! Some don't get it, some are asymptomatic, BUT if they get help at a young age it could make the difference between life and death. I do not have it, so all our geneticists and teams of doctors have concluded it is from this donor. He in fact deserves to know he has it, even if he has no active issues. I just want families of California Cryobank donor 3541 to know that their children may have it, or it may be an answer to some of them who are struggling for knowledge like we did for 2 years! It may help us as well to see if any sibs have it, and where/how they are progressing!"

2014: "I am the parent of two children who were born with a sperm donor. They are both in their early 30s. In the past 6 weeks we have discovered that they were born with a bad gene and they have a rare heart disease. With this gene, a person just drops dead with no warning. In checking my grandchildren, two of them, under the age of 10, carry the gene. My oldest child and the youngest grandchild have had surgery. My younger child is going to have a baby in December and that grandchild will have a 50 percent chance of getting the disease. Still testing etc to see what that treatment will be. I have had DNA testing done and I do not carry the gene. Doctors said it had to come from the donor."

2012: Child born with Cystic Fibrosis from New England Cryogenic Center (NECC). Related CBS story: Parents Sue Cryogenic Center Over Child’s Cystic Fibrosis

2012: At least nine children (Nordic Cryobank & California Cryobank) who were conceived with the sperm of a man with a genetically inherited disorder Neurofibromatosis (NF1 or von Recklinghausen disease). Related Human Reproduction case report: Gonosomal mosaicism for an NF1 deletion in a sperm donor: evidence of the need for coordinated, long-term communication of health information among relevant parties 

2009: London Women’s Clinic used chromosomally abnormal donor sperm to treat 11 women, including a couple who had to destroy 22 embryos created over a year of treatment. The Independent and BioNews.

2009: A child conceived using gametes from anonymous sperm and ova donors was diagnosed with spinal muscular atrophy type 1. Fertility and Sterility.

2009: New England Cryogenic Center (NECC) sued by a woman claiming that her children inherited genetic disorders. Other families who used this donor also report issues. Boston Herald.

2009: A Pacific Reproductive Services donor passed along HCM, a fatal heart disease, to 9 of his 22 known offspring. One child consequently died. JAMA.

2008: Idant Laboratories sued by a mother whose daughter was a carrier of the Fragile X gene (FMR1) as a result of donor sperm. The American Journal of Medical Genetics. Genomics Law Report: Strict Liability for Sperm?

2008: Two donor sibling cohorts from California Cryobank have a very high percentage of their children diagnosed with PDD-NOS (Autism). O Magazine.

2006: An International Cryogenics donor transmits Severe Congenital Neutropenia to at least 5 offspring. Journal of Pediatrics.

2006: A Fairfax Cryobank donor offspring diagnosed with Delta Storage Pool Deficiency (delta-SPD). Self Magazine.

2004: A Fairfax Cryobank donor transmitted familial Hemophagocytic Lymphohistiocytosis (FH) to twins; one child subsequently died. Self Magazine.

2003: An egg donor passes along Cystic Fibrosis. FindLaw: Better to Have Never Been Born? Wrongful Life Litigation

2002: A Dutch donor-conceived 18 children before being diagnosed with Autosomal Dominant Cerebellar Ataxia (ADCA). Journal of Medical Ethics.

2002: One recipient, two cases of spinal muscular atrophy (SMA). Fertility and Sterility.

2001: British-based donor of Australian origin with at least 43 offspring passed along potentially fatal genetic disorder, Opitz Syndrome. London Sunday Times.

2011: Donor-conception: 'I'd got to the bottom of a secret.' The Guardian.

1995: California Cryobank donor who donated 1500 vials of sperm transmitted Autosomal Dominant Polycystic Kidney Disease. Johnson v. California Cryobank.


Medical Update Statistics

Currently, many US facilities either refuse to update donor/offspring medical information or, even if they accept updates, refuse to share the information. Or they make the process of reporting so complex and expensive that donors and recipients simply cannot comply or afford it. In addition, US sperm banks do not have an accurate accounting of all children born from any one donor, so if an illness is reported, it is impossible to notify all potentially affected families.

  • 84% of sperm donors have never been contacted by their clinic(s) for medical updates.
  • 96% of egg donors have never been contacted by their clinic(s) for medical updates.
  • 23% of sperm donors felt that they had medical/genetic issues that would be important to share with families.
  • 31% of egg donors felt they had medical/genetic issues that would be important to share with families.
  • 94% of sperm donors would have accepted an offer for genetic testing, had it had been offered by their sperm banks.


Genetic and Medical Illnesses and Disorders


Inheritable diseases are caused by changes (mutations) in our genes. Humans have around 20,000 different genes, each of which has two copies — one copy inherited from each biological parent. Today there are more than 10,000 known inheritable diseases that affect approximately 1% of the population.

Mutations can be congenital. Mutations can be inherited from one or both parents; they can occur in the egg or sperm of a healthy parent and be transferred to a child; mutations can also occur in a fertilized egg. Whether a mutation in a disease-associated gene will lead to illness depends on the inheritance of the mutated gene.

Many people are carriers of one or more inheritable diseases but are unaware of their carrier condition or their reproductive risk.

"Researchers from Princeton University recently discovered that U.S. sperm banks differ widely in their testing protocols. They did a study of 27 provisionally qualified sperm donors and found many had genetic abnormalities. There were 30 genetic variants that were classified as 'pathogenic' and '66 with a high likelihood of causing gene dysfunction.' Whether these would actually cause problems in offspring would depend on the genetic makeup of the woman receiving the sperm. These researchers recommend more rigorous and standardized genetic testing of both donor males and recipient females."

The following is a partial list of genetic/medical illnesses and disorders reported by donors and recipient families on the Donor Sibling Registry. (This Excel spreadsheet shows some of the diseases listed below which are shown to be genetic.)