Question 31#

An Ashkenazi Jewish couple comes in to see you for preconception counseling. They are concerned that they might be at an increased risk for certain genetic disorders because of their ethnic background. The woman is 28 years old and tells you that neither side of the family has a history of any genetic disorders.

Which one of the following statements is the best advice for this couple?

A. They are at an increased risk of having a child with β-thalassemia

Certain autosomal recessive diseases are more common in individuals of Eastern European Jewish ancestry. ACOG recommends carrier screening for Tay-Sachs disease (carrier frequency 1/30), Canavan disease (carrier frequency 1/40), familial dysautonomia (carrier frequency 1/32), and cystic fibrosis (carrier frequency 1/29). Carrier screening tests are also available for several diseases that are less common, such as Fanconi anemia, Niemann-Pick disease, Bloom syndrome, and Gaucher disease. When only one partner is of Ashkenazi Jewish descent, that partner should be screened first. If this individual is found to be a carrier, then the partner should be offered screening. β-Thalassemias are hemoglobinopathies especially prevalent in individuals of Mediterranean or Asian heritage. The couple described is not at an increased risk of β-thalassemia and therefore does not need to undergo screening with hemoglobin electrophoresis. Based on ethnic background, this couple is not at increased risk of having a baby with a NTD. NTD follows a multifactorial inheritance pattern.

Question 32#

You have a patient who is very health conscious and regularly ingests several vitamins in megadoses and herbal therapies on a daily basis. She recently became a strict vegetarian because she heard it is the best diet for the developing fetus. She is going to attempt pregnancy and wants your advice regarding her diet and nutrition intake.

Which of the following should you recommend during her pregnancy?

A. Because herbal medications are natural, she may continue these dietary supplements during pregnancy

The use of herbal remedies is not recommended during pregnancy because such products are classified as dietary supplements and therefore are not FDA-regulated for purity, safety, and efficacy. In fact, the actual ingredients of many herbal substances are not even known. There is almost no data regarding the teratogenic potential of herbal medications in humans. Although a carefully planned vegetarian diet provides sufficient amino acids for pregnancy, it is not recommended that women assume a vegetarian diet during pregnancy. Animal sources of protein such as meat, poultry, fish, and eggs contain amino acids in the most desirable combinations. Strict vegetarians can give birth to infants who are low in vitamin B₁₂, because vitamin B₁₂ occurs naturally only in foods of animal origin. Pregnant women do not need to take vitamin A supplements because adequate amounts can be obtained in the diet; in addition, a very high intake of vitamin A has been associated with the type of congenital malformations seen with oral accutane use. Adequate vitamin C levels needed for pregnancy can be provided in a reasonable diet. No known fetal anomalies have been reported with vitamin C supplementation in pregnancy

Question 33#

An African-American woman presents to your office for her annual examination. She reports she was just released from the hospital after being treated for acute pain requiring narcotics. 

Match clinical situation described with the appropriate inheritance pattern.

 

A. Autosomal dominant

Sickle cell anemia is an autosomal recessive condition that is common in people of African origin. In low-oxygen conditions, the red cells become distorted (sickle), and this can lead to vasoocclusive crisis causing severe pain. Glucose6-phosphate dehydrogenase (G6PD) deficiency is X-linked recessive and is found predominantly in males of African and Mediterranean origin. 

Although the causes of clinical manifestations in G6PD deficiency are multifactorial (eg, sulfa drugs), the inheritance is not. Neurofibromatosis, whose occurrence is often sporadic (ie, a spontaneous mutation in 50%), is inherited as an autosomal dominant trait once the gene is in a family. The severity of the condition can be quite variable even within the same family. Cystic fibrosis is the most common autosomal recessive disorder in the white European population. Huntington disease is autosomal dominant.

Question 34#

A pregnant patient presents to you for prenatal care. Her parents are from Greece. She has a 2-year-old son, who was diagnosed with hemolytic anemia after he was treated for otitis media with a sulfonamide antibiotic. Her pediatrician gave her a list of antibiotics and foods that may trigger her son’s anemia.

Match clinical situation described with the appropriate inheritance pattern.

A. Autosomal dominant

Sickle cell anemia is an autosomal recessive condition that is common in people of African origin. In low-oxygen conditions, the red cells become distorted (sickle), and this can lead to vasoocclusive crisis causing severe pain. Glucose6-phosphate dehydrogenase (G6PD) deficiency is X-linked recessive and is found predominantly in males of African and Mediterranean origin. 

Although the causes of clinical manifestations in G6PD deficiency are multifactorial (eg, sulfa drugs), the inheritance is not. Neurofibromatosis, whose occurrence is often sporadic (ie, a spontaneous mutation in 50%), is inherited as an autosomal dominant trait once the gene is in a family. The severity of the condition can be quite variable even within the same family. Cystic fibrosis is the most common autosomal recessive disorder in the white European population. Huntington disease is autosomal dominant.

Question 35#

A patient presents to you for a well-woman examination. On physical examination she has a café au lait lesion on her back, along with multiple smooth, flesh-colored, dome-shaped papules scattered over her entire body.

Match clinical situation described with the appropriate inheritance pattern.

A. Autosomal dominant

 Sickle cell anemia is an autosomal recessive condition that is common in people of African origin. In low-oxygen conditions, the red cells become distorted (sickle), and this can lead to vasoocclusive crisis causing severe pain. Glucose6-phosphate dehydrogenase (G6PD) deficiency is X-linked recessive and is found predominantly in males of African and Mediterranean origin. 

Although the causes of clinical manifestations in G6PD deficiency are multifactorial (eg, sulfa drugs), the inheritance is not. Neurofibromatosis, whose occurrence is often sporadic (ie, a spontaneous mutation in 50%), is inherited as an autosomal dominant trait once the gene is in a family. The severity of the condition can be quite variable even within the same family. Cystic fibrosis is the most common autosomal recessive disorder in the white European population. Huntington disease is autosomal dominant.