Concomitant Gallbladder Agenesis with Methimazole Embryopathy.

Area of Science:

• Medical Genetics
• Developmental Biology
• Pediatric Surgery

Background:

• Methimazole embryopathy results from maternal methimazole exposure in early pregnancy, leading to fetal malformations.
• Known malformations include choanal atresia, esophageal atresia, aplasia cutis, and omphalocele.
• Gallbladder agenesis, while sometimes associated with other anomalies, has not been previously linked to methimazole embryopathy.

Observation:

• A male neonate presented with omphalocele, omphalomesenteric fistula, and scalp defect, diagnosed with methimazole embryopathy.
• Prenatal and postnatal imaging failed to identify the gallbladder, suggesting gallbladder agenesis.
• The infant also exhibited hypothyroidism, requiring levothyroxine treatment.

Findings:

• This case represents the first documented instance of concomitant gallbladder agenesis and methimazole embryopathy.
• Dilatation of the biliary duct was noted on MRI despite the absence of the gallbladder.
• The infant remained asymptomatic at six months post-discharge, with hypothyroidism managed by levothyroxine.

Implications:

• The co-occurrence of gallbladder agenesis and methimazole embryopathy highlights a potential teratogenic effect of methimazole on biliary system development.
• Patients with gallbladder agenesis, particularly those with a dilated common bile duct, require lifelong monitoring for potential complications like choledocholithiasis or biliary tumors.
• This case underscores the importance of comprehensive evaluation and long-term surveillance in infants diagnosed with methimazole embryopathy and associated anomalies.