What condition would be suggested by a history of prolonged neonatal jaundice and poor weight gain in an infant?

The presence of prolonged neonatal jaundice coupled with poor weight gain in an infant strongly suggests congenital hypothyroidism. This condition, which is often detected through newborn screening, occurs due to an insufficient production of thyroid hormones, critical for normal growth and development.

In infants with congenital hypothyroidism, the lack of thyroid hormones can lead to a delay in metabolism and cause symptoms such as prolonged jaundice, as bilirubin metabolism can be impaired. Additionally, the infant may experience poor weight gain due to reduced appetite and slowed growth associated with the lack of these essential hormones.

While prolonged jaundice can also be seen in other conditions, the combination with poor weight gain points more specifically to congenital hypothyroidism as a likely cause, making it a critical diagnosis to consider in such clinical scenarios.