Large tongue, neonatal jaundice, constipation (182/1700)

An 8m infant presented with FTT and constipation. Exam: large tongue and hx of prolonged
neonatal jaundice. What is the most likely dx?
a. Downs syndrome
b. Fragile X syndrome
c. Praderwilli syndrome
d. DiGeorge syndrome
e. Congenital hypothyroidism
































answer E

CONGENITAL HYPOTHYROIDISM

Epidemiology

• incidence: 1:4,000-1:20,000 newborns births; F:M = 2:1

• one of the most common preventable causes of intellectual disability

Etiology

• may be classified as permanent primary, central, or transient hypothyroidism

• ~85% of primary cases are sporadic (mostly thyroid dysgenesis), remaining 15% are hereditary

(mostly inborn errors of thyroid synthesis)

• causes of transient hypothyroidism: maternal antibody-mediated, iodine deficiency (rare in developed countries), prenatal exposure to antithyroid medications

Clinical Presentation

• history and physical exam

- usually asymptomatic in neonatal period because maternal T4 crosses the placenta

- prolonged jaundice, constipation, sluggish, hoarse cry, lethargy, poor feeding, macroglossia,

coarse facial features, large fontanelles, umbilical hernia

Investigations

- diagnosis through newborn screening of TSH or free T4; abnormal results should be confirmed with serum levels from venipuncture

Management

• thyroxine replacement