Pediatric Examination and Board Review (148 page)

14.
(D)
OI is a result of a disorder of collagen synthesis and is the most prevalent of the osteoporosis syndromes in childhood. OI is characterized by fractures and skeletal deformities. Some affected patients die in the newborn period with extreme fragility of bone and numerous fractures. Others manifest bone fragility later in life and live a normal lifespan. Ellis-Van Creveld syndrome is characterized by polydactyly, short distal extremities, and nail hypoplasia.

15.
(C)
There is great overlap in the clinical subtypes; all are a result of mutations in collagen. The different clinical severity is a result of different genetic mutations, their severity, and their effect on collagen synthesis and function. The clinical features of each subtype are all described correctly except for type III. OI type III has severe bone fragility and multiple fractures, which lead to progressive skeletal deformity, and severe short stature.

16.
(D)
In OI type I, hearing loss is rare before the end of the first decade but affects most patients by the fifth decade. Type II is typically lethal so there is little associated hearing loss described. Hearing impairment is not a common feature in OI type III.

S
UGGESTED
R
EADING

Spranger JW, Brill PW, Poznanski A.
Bone Dysplasias
.New York, NY: Oxford University Press; 2002.

Chapter 11

HEMATOLOGY AND ONCOLOGY

CASE 87: A NEONATE WITH HYPERBILIRUBINEMIA

You are called to evaluate a 4-day-old infant in the nursery for worsening jaundice. The patient is the first child of a 32-year-old mother, who had an uncomplicated full-term pregnancy and normal spontaneous vaginal delivery. The mother is otherwise healthy but has a sister who had her gallbladder removed as a child. The infant has been formula fed and has been eating and stooling normally. The total bilirubin level is 19.2 mg/dL, with a direct fraction of 0.3 mg/dL.

On physical examination, the infant is jaundiced but otherwise well, with no other significant physical findings.

SELECT THE ONE BEST ANSWER

1.
The differential diagnosis of the unconjugated hyperbilirubinemia in this child includes which of the following?

(A) biliary atresia

(B) alpha
₁
-antitrypsin deficiency

(C) ABO blood type incompatibility

(D) Caroli syndrome

(E) Sickle cell anemia

2.
The laboratory evaluation of this infant’s hyperbilirubinemia should include all of the following except

(A) complete blood count with smear

(B) indirect and direct Coombs test

(C) prothrombin time (PT)/partial thromboplastin time (PTT)

(D) maternal blood type

(E) reticulocyte count

3.
Which of the following combinations of parents’ blood types place an infant at highest risk for hemolytic anemia?

(A) maternal Rh negative, paternal Rh negative, first child

(B) maternal Rh negative, paternal Rh positive, second child

(C) maternal type O, paternal type O, first child

(D) maternal type AB, paternal type B, second child

(E) maternal type AB, paternal type A, first child

4.
The differential diagnosis of a neonate with hemolytic anemia includes all of the following except

(A) pyruvate kinase deficiency

(B) ABO incompatibility

(C) Crigler-Najjar syndrome

(D) hereditary spherocytosis

(E) Rh disease

5.
Erythroblastosis fetalis is characterized by all of the following except

(A) elevated amniotic fluid bilirubin levels

(B) fetal anasarca

(C) decreased umbilical cord nucleated red blood cells

(D) fetal hepatosplenomegaly

(E) elevated reticulocyte count

6.
Treatment of the infant with Rh-hemolytic disease could include which of the following?

(A) red blood cell exchange transfusion with neonatal cross-matched blood

(B) red blood cell transfusion with maternal crossmatched blood

(C) fresh frozen plasma every 8 hours

(D) intravenous immunoglobulin for the mother before delivery

(E) cryoprecipitate transfusion

7.
The direct Coombs test is an evaluation for which of the following?

(A) anti-white blood cell antibodies in the serum

(B) anti-platelet antibodies bound to the patient’s platelets

(C) antibodies against red blood cells that are bound to the red blood cell membrane

(D) serum antibodies against all blood cells

(E) Rh antibodies

8.
Physiologic anemia of infancy occurs at what age for healthy full-term infants?

(A) 1-2 days old

(B) 2-3 weeks old

(C) 2-3 months old

(D) 10-12 months old

(E) 3-6 months old

9.
Which of the following is the best treatment for physiologic anemia of infancy?

(A) oral ferrous sulfate

(B) careful observation

(C) folic acid supplementation

(D) monthly red blood cell transfusions

(E) vitamin B
₁₂
supplementation

10.
G6PD (glucose-6-phosphate dehydrogenase) deficiency is
least
common in which of the following ethnic groups?

(A) northern African

(B) northern European

(C) southern Asian

(D) southern European

(E) South America

11.
G6PD deficiency is inherited in what fashion?

(A) X-linked

(B) autosomal recessive

(C) autosomal dominant with variable penetrance

(D) mitochondrial

(E) autosomal recessive with variable penetrance

12.
The presence of Heinz bodies on the peripheral blood smear is a feature of which of the following disorders?

(A) G6PD deficiency

(B) autoimmune hemolytic anemia

(C) neonatal alloimmune thrombocytopenia

(D) sickle cell disease

(E) spherocytosis

13.
Which of the following, when ingested, is
not
associated with hemolytic crisis in patients with G6PD deficiency?

(A) primaquine

(B) trimethoprim-sulfamethoxazole

(C) methylene blue

(D) acetaminophen

(E) moth balls

14.
Which of the following is not a feature of hemolytic crises in patients with G6PD deficiency?

(A) hemoglobinuria

(B) splenomegaly

(C) pulmonary infiltrates

(D) jaundice

(E) elevated reticulocyte count

15.
Hereditary spherocytosis is most commonly caused by a defect in which red blood cell protein?

(A) hemoglobin

(B) spectrin

(C) pyruvate kinase

(D) ankyrin

(E) G6PD

16.
Which of the following laboratory tests would be most useful in diagnosing hereditary spherocytosis?

(A) Coombs test

(B) osmotic fragility test

(C) platelet aggregation test

(D) hemoglobin electrophoresis

(E) serum iron

17.
Which of the following is the most effective long-term treatment for patients with hereditary spherocytosis?

(A) monthly exchange transfusions

(B) splenectomy