Genetic Disease Details

Chromosome Analysis

The chromosomes in our cells are the physical units that contain the genetic information (DNA or genes) necessary for all growth and development necessary throughout our lifetime.  Some healthy individuals carry rearrangements in the physical structure of their chromosomes.  These individuals may be at increased risk of infertility, miscarriage and birth defects and/or mental retardation in offspring.  It is not possible to determine if anyone has a normal chromosome structure simply by a physical examination or review of medical history. A genetic chromosome analysis (karyotype) on a blood sample will give us the answer. Thus, chromosome analysis is done on all sperm donors. Applicants are excluded from the program if the testing is not normal. Fairfax Cryobank is one of a few sperm banks that perform this important test on all donors.

Cystic Fibrosis

Cystic fibrosis (CF) is a common recessive disease, most frequently seen in the Caucasian population but has been reported in individuals of all ethnicities.  In the United States approximately 1 person in 2500 is affected with CF. Individuals with CF usually have severe lung disease and other problems leading to chronic illness and shortened lifespan. CF carriers ordinarily do not exhibit symptoms of the disease.

DNA testing of donor applicants significantly reduces (but does not eliminate) the chance that a donor is a carrier of CF:

  • from 1 in 29 to 1 in 325 in the Caucasian population
  • from 1 in 46 to 1 in 162 in the Hispanic-American population
  • from 1 in 65 to 1 in 338 in the African-American population
  • from 1 in 26 to 1 in 834 in the Ashkenazi Jewish population 

Fairfax Cryobank is the first and only sperm bank to retroactively screen ALL donors on our register for at least 86 CF mutations.  Please click here to learn more about CF 86 screening and to understand why all CF screening is not equal.

Sickle Cell disease

 Sickle cell anemia is an autosomal recessive disease caused by mutations in the beta-globin gene and is found frequently in individuals of African and Hispanic ancestry. When both parents are carriers, each child has a 25% chance of having the disease. The carrier frequency of sickle cell trait (also known as hemoglobin S trait) is approximately 1 in 10 for individuals of African descent, and lower for other ethnic groups. A less common beta-globin mutation known as hemoglobin C trait is also more common in African and Hispanic ancestry. Sickle cell disease and Hemoglobin SC disease may result in a number of medical problems such as painful joint and vascular episodes, increased risk of infection, and increased risk of stroke. Fairfax Cryobank currently screens all donors regardless of ethnicity for the presence of both hemoglobin S and C trait.

Tay Sachs disease - Biochemical Carrier Screening and DNA screening

Tay Sachs disease occurs when the enzyme hexosaminidase A is not produced within the cells. Hexosaminidase A helps to breakdown fatty material known as lipids. With little or no hexosaminidase A present, this material builds up in the brain cells. In the most common form of Tay Sachs disease, the brain cells are irreversibly and progressively damaged. Unfortunately there is no current treatment for Tay Sachs disease, and death occurs between ages 3-5. The American College of Obstetrics and Gynecology and the American College of Medical Genetics recommend carrier screening for Tay Sachs disease in all individuals of ethnic background with an elevated risk to carry Tay Sachs disease.  Individuals of Ashkenazi Jewish, French-Canadian and Cajun ancestry are at elevated risk to carry Tay Sachs disease; the carrier frequency is about 1 in 30. It is inherited as an autosomal recessive disease, and when both parents are carriers, each child has a 25% chance of having the disease. There are two ways to test for carriers, by enzyme testing and DNA testing. Enzyme testing detects approximately 98% of carriers and DNA testing detects about 92% of carriers of Ashkenazi Jewish ancestry. Fairfax Cryobank tests all donors with Ashkenazi Jewish, French Canadian, and/or Cajun ancestry by both enzyme and DNA testing methods.

Thalassemia

 Thalassemia is a term that describes several common genetic forms of anemia found primarily in individuals of Asian, African, Middle Eastern and Mediterranean descent. They are frequently referred to as beta-thalassemia (more common in Mediterranean and African background) or alpha-thalassemia (more common in Asian ancestry). While anemia is the most common manifestation, any of the forms of thalassemia may involve a variety of medical problems ranging from fetal death to the need for lifelong blood transfusions and other complications. Affected individuals and carriers of the most common forms of beta and alpha thalassemia may be identified by blood tests thus reducing the risk of a donor fathering an affected child. Fairfax Cryobank performs this screening on all appropriate donor applicants.

Canavan Disease

 Children with Canavan disease have a deficiency of the enzyme aspartoacylase (ASP). Degenerative changes in the brain lead to muscle weakness, seizures, feeding difficulties and blindness, with death occurring by age 10. Approximately 1 in 40 individuals of Ashkenazi Jewish descent are carriers of Canavan disease. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 95% of carriers. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Canavan disease.

Gaucher Disease

 Individuals with Gaucher Disease have a deficiency of the enzyme glucocerebrosidase (GBA). In the mild form, patients have adult-onset enlargement of the liver and spleen, and deformity and fractures of the femur. Enzyme replacement therapy is available. The severe form has childhood onset, with the most severe cases having neurological involvement and death by age 2. In the Ashkenazi Jewish the adult-onset form that is most common, with a carrier frequency of 1 in 12. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 95% of carriers. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Gaucher disease.

Bloom Syndrome

 Children with Bloom Syndrome have a deficiency in a DNA repair enzyme. They have normal intelligence but poor growth, sun-sensitivity, immune system deficiencies, and high risk for cancer. Cancer is usually the cause of death in young adulthood. There is no cure. Individuals of Ashkenazi Jewish descent have a 1 in 100 risk to be a carrier. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 97% of carriers. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Bloom disease.

Fanconi Anemia Type C

 Individuals with Fanconi Anemia have anemia with progression bone marrow failure as well as congenital malformation of the heart, kidneys, and/or limbs. There is a high risk for leukemia. There are several types of Fanconi Anemia. Among individuals of Ashkenzi Jewish ancestry there is a 1 in 90 risk to carry Fanconi Anemia type C. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 98% of carriers of type C. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Fanconi Anemia type C.

Niemann-Pick Disease - Type A

 Children with Neimann-Pick Disease Type A have a deficiency of the enzyme acid sphingomyelinase (ASM). They have failure to thrive, an enlarged liver and spleen, respiratory insufficiency, and neurological degeneration. Death occurs by age 3 and currently there is no treatment. There are several types of Niemann-Pick disease. Individuals of Ashkenazi Jewish heritage have a 1 in 90 risk to carry Niemann Pick Type A. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 95% of carriers of type A. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Niemann-Pick disease type A.

Mucolipidosis Type IV

 Children with Mucolipidosis Type IV have a deficiency in the protein mucolipin-1. They have corneal clouding and other eye problems, as well as developmental and motor delay. Individuals frequently live into adulthood with a significantly affected quality of life. Mucolipidosis Type IV occurs in the highest frequency in persons of Ashkenazi Jewish heritage, where 1 person in 122 is a carrier. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 96% of carriers. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Mucolipidosis type IV.

Familial Dysautonomia

 Children with Familial Dysautonomia have a deficiency of the protein IKK complex-associated protein leading to progressive deterioration of the autonomic nervous system. This causes insensitivity to pain, lack of overflow tears, vomiting crises, abnormal cardiovascular and thermoregulatory responses, and gastrointestinal dysfunction. The median age of death is 30 years. Individuals of Ashkenazi Jewish descent have a 1 in 30 risk to be a carrier. When both parents are carriers, each child has a 25% chance of having the disease. Testing individuals of Ashkenazi Jewish ancestry detects 99% of carriers. Fairfax Cryobank tests all donors with Ashkenazi Jewish descent for Familial Dysautonomia.