Review Question - QID 106998

This patient's clinical presentation is consistent with Fanconi's anemia (FA), which is caused by a defect in DNA repair.

FA is an autosomal recessive disorder caused by defects in DNA repair. It typically presents with poor growth, morphologic abnormalities (especially thumb malformations), and a macrocytic anemia. FA is extremely rare, but is more common in Ashkenazi Jews and South Africans of Afrikaner decent. Patients may develop anemia, thrombocytopenia, and leukopenia, and treatment includes hematopoeitic stem cell transplant, hematopoeitic growth factors, and androgens.

Janus and Moerschel discuss anemia in children. They note that a normal reticulocyte count effectively rules out FA in patients with anemia. Other causes of decreased red blood cell production include Diamond-Blackfan anemia and infection.

Verlinsky et al. discuss the use of preimplantation genetic diagnosis (PGD) to produce a child with an HLA type matching that of a living child with FA. They report that this is the first time that PGD has been used for the purpose of producing a child who can serve as a bone marrow transplant, and they note the possible ethical implications of this treatment.

Figure A shows a typical thumb malformation in a patient with FA. Figure B shows cafe-au-lait spots, which are common in patients with FA. Illustration A shows a bone marrow biopsy showing aplastic anemia that would be typical in a patient with FA.

Incorrect Answers:
Answer 2: Turner syndrome is associated with a 45,XO karyotype. Patients (females) typically have wide-spaced nipples, a webbed neck, and infertility due to premature ovarian failure.
Answer 3: Congential adrenal hyperplasia is caused by a 21-hydroxylase deficiency. It typically presents with abnormal genetalia in girls and early puberty in boys.
Answer 4: Fragile X syndrome is associated with trinucleotide repeat expansion, and is characterized by autism spectrum disorders and macro-ochordism.
Answer 5: Prader-Willi syndrome is associated with a missing portion of chromosome 15 and is characterized by severe obsession with food, obesity, and mental retardation.