An uncommon cause of unconjugated hyperbilirubinemia

HOSP #		WARD	Red Cross Endocrinology
CONSULTANT	Dr Jody Rusch	DOB/AGE	27 day female

Abnormal Result

TSH > 100

Free T4: 0.5 pmol/L

Presenting Complaint

Patient was brought to the ER being lethargic.

History

Term Neonate; Had a history of profound jaundice after birth, with unconjugated hyperbilirubinemia.

The patient’s mother lives in Athlone, gave birth at Carl Bremer hospital where a cord blood TSH was done, but results not available at the time.

Examination

No overt abnormalities on examination was found, except the single sign of jaundice.

No defects at the base of the tongue was observed.

No abnormalities in the neck was observed.

Laboratory Investigations

TSH > 100

Free T4: 0.5 pmol/L

Other Investigations

The patient had an ultrasound of the abdomen done (since it was the first occurence of hyperbilirubinemia, and in fact is termed pathological jaundice).

Cord blood TSH was retrospectively reviewed as being 178 uIU/ml.

Final Diagnosis

Congenital hypothyroidism

Take Home Message

Congenital hypothyroidism (CH) is thyroid hormone deficiency present at birth. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent intellectual disability. Infants born with congenital hypothyroidism may show no symptoms, or may display mild symptoms that often go unrecognized as a problem. Significant deficiency may cause lethargy, hypotonia, hoarse cry, infrequent bowel movements, significant jaundice, and hypothermia.

Causes of congenital hypothyroidism include

• iodine deficiency (most common cause)
• developmental defect in the thyroid gland, either due to a genetic defect or a biochemical defect in thyroxine production
• pituitary defects – congenital hypopituitarism (present at birth) may be the result of complications around delivery, or may be the result of insufficient development (hypoplasia) of the gland, sometimes in the context of specific genetic abnormalities.