Other Free Encyclopedias » Medicine Encyclopedia » Genetics in Medicine - Part 1 » Birth Defects - Various Causes, Various Treatments, Single-gene Mutations, Autosomal Dominant Disorders, Functional Birth Defects

Birth Defects - Maternal Conditions

genetic clinical diabetes called child phenylalanine

Birth defects can also result from physical conditions affecting the health of the mother. One common maternal condition associated with birth defects is diabetes mellitus, a multifactorial disorder. Mothers with diabetes have a two-to three-fold times greater risk of having a child with birth defects than the general population if their condition is not well controlled. However, good glucose control has been shown to correlate with a decreased risk of congenital malformations. Characteristic diabetic malformations include cardiovascular, craniofacial, genitourinary, gastrointestinal, and neurological abnormalities. The risk that the child born of a mother with diabetes mellitis will also develop diabetes as an adult is 1 to 3 percent.

Another maternal condition giving rise to birth defects is maternal phenylketonuria (PKU). This is an autosomal recessive disorder in which an enzyme called phenylalanine hydroxylase is defective. This enzyme normally converts a substance in the blood called phenylalanine to another substance called tyrosine. As a result, phenylalanine levels are high, resulting in mental retardation, microencephaly, growth retardation, cardiac problems, seizures, vomiting, and hyperactivity. Other traits associated with PKU are fair hair and skin and blue eyes. PKU can be effectively managed through changes in the diet, and women who have appropriately managed their diet can have pregnancies with healthy offspring.

Nancy S. Green

and Terri Creeden

Bibliography

Batshaw, Mark L. When Your Child Has a Disability: The Complete Sourcebook of Daily and Medical Care. Baltimore, MD: Paul H. Brooks Publishing, 2001.

"Leading Categories of Birth Defects." March of Dimes Perinatal Data Center, 2000.

Internet Resource

National Organization of Rare Disorders. <http://www.rarediseases.org>.

The average IQ of an individual with Down syndrome is 55. Most tests cite an IQ of 100 as "average."

[back] Birth Defects - Teratogen Exposure

User Comments

The following comments are not guaranteed to be that of a trained medical professional. Please consult your physician for advice.

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or