A 5-day-old child presents with intractable seizures. He had rashes all over the body. Blood examination showed hyperammonemia and lactic acidosis. The probable diagnosis is –

Organic aciduria (organic acidemia) Organic aciduria is a term used to classify a group of metabolic disorders which disrupt normal amino acid metabolism, particularly branched-chain amino acids (isoleucine, leucine, valise) causing a build of acids which are usually not present. The main types of organic acidemia are : - i) Methylnzalonic acidemia     ii) Propionic acidenzia        iii) Isoavleric acidemia iv) Maple syrup urine disease vi) Giutaric acidemia            v) Combined (multiple) carboxylase deficiency Clinical manifestations Neurological damage → Mental retardation, Seizures, Lethargy, Vomiting. Developmental delay                Hypoglycemia                            Ketoacidosis         Malnutrition      Hypotonia      Hyperammonemia      Poor feeding and slow growth   Metabolic acidosis (Lactic acidosis)   Rash, alopecia and ataxia in some organic aciduria.             Mitochondrial encephalopathy (MELAS) Encephalopathy Lactic acidosis Stroke-like episodes → Blindness, paralysis, vomiting. Disorders of the urea cycle Ammonia is mostly derived from the catabolism of amino acid and is converted to an amino group in urea by enzymes of the urea cycle. So, defects in enzymes of urea cycle cause → i) Hyperammonemia            ii) Encephalopathy      iii) Vomiting