An infant unable to feed properly, weak, and not gaining proper weight. His mother comes to OPD with complaints of multiple episodes of urination and baby cries each time he passes urine. She also tells that the baby often smells of rotten fish in his urine and his sweat. Which of the following would you test in the urine of the infant?

Tri methylaminuria Fish odour syndrome (autosomal recessive) is a rare metabolic disorder in which enzyme defect is Flavin containing mono-oxygenase-3 (FMO3). This enzyme uses riboflavin as a co-factor. In this syndrome, Affected individuals have a reduced capacity to metabolize trimethylamine into trimethylamine N-oxide (odourless). Trimethylamine is volatile compound, which gives off a strong fishy smell in urine, sweat, and expired air. Treatment Restriction of foods rich in trimethyl amine (fish, egg, liver, nuts, grains) Riboflavin supplement Extra Information: Various diseases and their odor is an impoant question being asked frequently these days: Inborn Error of Metabolism Urine Odour Phenylketonuria (PKU) Mousy/ Musty Maple Syrup Urine Disease (MSUD) Maple Syrup/ Burnt Sugar Isovaleric Acidemia Sweaty feet/ Cheesy Hawkinsinuria Swimming Pool Glutaric Acidemia Sweaty Feet 3-Hydroxy-3-Methyl Glutaric Aciduria Cat Urine Multiple Carboxylase Deficiency Tomcat Urine Hypermethioninemia Boiled Cabbage Tyrosinemia Boiled Cabbage, Rancid Butter Trimethylaminuria Rotten fish Diabetic Ketoacidosis Fruity Urinary Tract Infections Foul smell