Biotinidase Deficiency With Suspected Sotos Syndrome: A Rare Entity.

Biotinidase deficiency (BTD) is a rare yet treatable metabolic autosomal recessive (AR) disorder in which the body is unable to recycle the vitamin biotin. Early diagnosis and treatment can be life-saving, but some symptoms of the disease are irreversible, and the condition can even prove to be fatal if not correctly diagnosed and managed. Here we present a case of a six-month-old child who presented with cough, fever, and difficulty in breathing. Respiratory examination revealed deep subcostal and intercostal recessions, bilateral crepitations, and wheezes. On central nervous system (CNS) examination, the baby had a low Glasgow Coma Scale (GCS) score of 10 while the tone was decreased, and bulk was increased in all four limbs. Chest X-ray revealed haziness at the right middle and lower lobes. Antibiotics were started keeping pneumonia, bronchiolitis, and sepsis in mind along with an initial diagnosis of inborn error of metabolism (IEM). As the patient's condition deteriorated, nasal bubble continuous positive airway pressure (CPAP) and nebulization were provided and later put on a ventilator. Arterial blood gases (ABGs) showed severe metabolic acidosis and compensatory respiratory alkalosis with an anion gap of 15. Urine profile for organic acid was performed, and the diagnosis of sepsis with BTD was made. Unfortunately, our patient expired on the fourth day of admission before a biotin injection could be searched and administered. Moreover, our patient was also suspected of a possible Sotos syndrome, which is a rare genetic disorder characterized by excessive growth in the initial years of life. The case highlights the significance of the diagnosis of such metabolic disorders in the natal period of life and their immediate management.