Medical Update- CLI Donor 1115
CLI Moderator
Senior Member
One offspring has been reported with a neural tube defect (encephalocele). Another child was found to be a carrier for Galactosemia.
What are Neural Tube Defects (NTDs)?
Neural tube defect (NTDs) is one of the most common birth defects, occurring in approximately one in 1,000 live births in the United States. It is diagnosed at birth and hence a child born healthy is not at risk. An NTD is an opening in the spinal cord or brain that occurs very early in human development. In about the 3rd or 4th weeks of pregnancy, specialized cells in the dorsal region begin to fuse and curl up which rolls into a tube (the neural tube) after the baby is conceived. When the neural tube does not close completely, an NTD develops.
What causes NTDs?
Neural tube defects are caused by multiple genes and environmental factors which are not completely understood. Research has shown that women with folic acid deficiencies also have a higher chance of having a child with a neural tube defect and it is believed they account for the majority of cases. Taking folic acid does not completely negate the risk of neural tube problems, but it does significantly reduce the risk. Other potential causes can include maternal diabetes, maternal obesity, and environmental toxins such as cigarette smoke.
The genetic contribution is not well understood. A child from this donor is not believed to be at increased risk and the same risk as seen in the general population risk of about 1/500. Risks are reduced by taking folic acid supplements before and during pregnancy. This is now standard of care for all pregnancies.
What is Galactosemia?
The child reported was not sick with this disease but was determined to be a carrier. He could have gotten this gene from either his mother or the donor, hence the donor has 50% chance to be a carrier. Testing on the donor and child’s mother was not completed. Consequently, his children have a 25% chance of being a carrier. Only if BOTH parents are carriers, is the pregnancy at risk. Galactosemia (Galactose-1-phosphate uridyltransferase (GALT) deficiency) is a rare autosomal recessive disorder present at birth. Newborn screening programs test for this disease before newborns leave the hospital in the US. Children with Galactosemia have no apparent birth defects and do not appear to be abnormal at birth, but the enzyme deficiency causes accumulation of metabolites that can result in feeding problems, failure to thrive, liver damage, bleeding and sepsis if the condition is not recognized and lactose removed from their diets early in life. If you have a healthy child, and the newborn screening results were normal, you do not need to worry that your child will develop this condition.
In the general population, 1/80-90 (about 1%) are carriers for Galactosemia. Carriers of Galactosemia are entirely healthy and do not become ill. And only if BOTH biological parents are carriers, is the offspring at risk. It is therefore important to consider carrier testing in children from this donor, and if positive, their partners should be tested. A child from this donor, before testing, has a 1/1600 chance of having an affected child themselves. With testing, the risk can be more accurately defined. In addition, Newborn Screening results can be utilized to reassure families that children are not affected.
A certified genetic counselor, Suzanne Seitz, MS, is available to you to answer your questions. She can be reached at 703-876-3869 or sseitz@givf.com
What are Neural Tube Defects (NTDs)?
Neural tube defect (NTDs) is one of the most common birth defects, occurring in approximately one in 1,000 live births in the United States. It is diagnosed at birth and hence a child born healthy is not at risk. An NTD is an opening in the spinal cord or brain that occurs very early in human development. In about the 3rd or 4th weeks of pregnancy, specialized cells in the dorsal region begin to fuse and curl up which rolls into a tube (the neural tube) after the baby is conceived. When the neural tube does not close completely, an NTD develops.
What causes NTDs?
Neural tube defects are caused by multiple genes and environmental factors which are not completely understood. Research has shown that women with folic acid deficiencies also have a higher chance of having a child with a neural tube defect and it is believed they account for the majority of cases. Taking folic acid does not completely negate the risk of neural tube problems, but it does significantly reduce the risk. Other potential causes can include maternal diabetes, maternal obesity, and environmental toxins such as cigarette smoke.
The genetic contribution is not well understood. A child from this donor is not believed to be at increased risk and the same risk as seen in the general population risk of about 1/500. Risks are reduced by taking folic acid supplements before and during pregnancy. This is now standard of care for all pregnancies.
What is Galactosemia?
The child reported was not sick with this disease but was determined to be a carrier. He could have gotten this gene from either his mother or the donor, hence the donor has 50% chance to be a carrier. Testing on the donor and child’s mother was not completed. Consequently, his children have a 25% chance of being a carrier. Only if BOTH parents are carriers, is the pregnancy at risk. Galactosemia (Galactose-1-phosphate uridyltransferase (GALT) deficiency) is a rare autosomal recessive disorder present at birth. Newborn screening programs test for this disease before newborns leave the hospital in the US. Children with Galactosemia have no apparent birth defects and do not appear to be abnormal at birth, but the enzyme deficiency causes accumulation of metabolites that can result in feeding problems, failure to thrive, liver damage, bleeding and sepsis if the condition is not recognized and lactose removed from their diets early in life. If you have a healthy child, and the newborn screening results were normal, you do not need to worry that your child will develop this condition.
In the general population, 1/80-90 (about 1%) are carriers for Galactosemia. Carriers of Galactosemia are entirely healthy and do not become ill. And only if BOTH biological parents are carriers, is the offspring at risk. It is therefore important to consider carrier testing in children from this donor, and if positive, their partners should be tested. A child from this donor, before testing, has a 1/1600 chance of having an affected child themselves. With testing, the risk can be more accurately defined. In addition, Newborn Screening results can be utilized to reassure families that children are not affected.
A certified genetic counselor, Suzanne Seitz, MS, is available to you to answer your questions. She can be reached at 703-876-3869 or sseitz@givf.com