[Trimethylaminuria: three different mutations in a single family].

Area of Science:

• Biochemistry
• Genetics
• Metabolic Disorders

Background:

• Primary trimethylaminuria (Fish Odor Syndrome) is a rare genetic metabolic disorder.
• Characterized by the accumulation of trimethylamine (TMA) in body fluids.
• TMA is a volatile compound responsible for a strong fishy odor.

Observation:

• A case of an 8-month-old healthy patient presenting with persistent fishy body odor after dietary fish introduction.
• Initial medical consultations did not identify the disorder, delaying diagnosis until age three.
• Maternal persistence led to referral and genetic testing.

Findings:

• Genetic testing confirmed primary trimethylaminuria in the patient.
• Identified an unnoticed paternal diagnosis of the condition.
• Detected three distinct mutations within the family, highlighting genetic heterogeneity.

Implications:

• Highlights that primary trimethylaminuria can present subtly and remain undiagnosed for years.
• Emphasizes the importance of clinical suspicion and appropriate genetic testing for diagnosis.
• Facilitates early clinical management and genetic counseling for affected families.