Congenital Hypothyroidism: An Unusual Combination of Biochemical Abnormalities

Area of Science:

• Pediatrics
• Endocrinology
• Neonatology

Background:

• Congenital hypothyroidism (CHT) is a common endocrine disorder in newborns.
• Prolonged jaundice and elevated hepatic transaminases are typically investigated for other causes.
• The association between CHT and these clinical findings is rarely reported.

Purpose of the Study:

• To report a case of CHT presenting with indirect hyperbilirubinemia and elevated liver enzymes.
• To highlight the resolution of these biochemical abnormalities with thyroid hormone replacement therapy.
• To suggest CHT as a differential diagnosis in neonates with unexplained jaundice and hepatic transaminase elevation.

Main Methods:

• Case presentation of a 45-day-old female infant.
• Biochemical investigations including bilirubin, liver function tests (AST, ALT), and thyroid profile (TSH, free T3, free T4).
• Diagnostic imaging including radionuclide scan and ultrasonography of the neck.

Main Results:

• Infant presented with prolonged jaundice, indirect hyperbilirubinemia, and elevated AST/ALT levels.
• Thyroid function tests revealed low free T3/T4 and markedly elevated TSH, consistent with thyroid agenesis.
• Thyroxin therapy led to significant improvement in bilirubin levels and normalization of AST/ALT within 15 days.

Conclusions:

• Elevated hepatic transaminases and indirect hyperbilirubinemia can be presenting features of congenital hypothyroidism in infants.
• Thyroxin replacement therapy is effective in resolving these biochemical abnormalities.
• This case underscores the importance of considering CHT in the differential diagnosis, potentially avoiding extensive investigations.