Case 6: Failure to Thrive with Congenital Glaucoma in a 2-month-old Girl

Presentation

A 2-month-old girl presents to her pediatrician for a regular checkup. Failure to gain weight, unmet developmental milestones, and hypotonia are observed, and the patient is admitted for evaluation for failure to thrive. The patient was born by spontaneous vaginal delivery at 39 weeks with a body weight of 2,690 g. Her newborn screening test result was normal. Shortly after birth, she was noted to have left buphthalmos associated with increased intraocular pressure (IOP) and underwent left eye trabeculotomy 10 days after birth. Postoperatively, she experienced hypothermia to 91.4°F (33.0°C), an elevated ammonia level to 126 μg/dL with mild metabolic acidosis, and difficulty regaining consciousness. She was admitted to the hospital for observation, and her ammonia level returned to normal without treatment. No further evaluation was initiated because the hyperammonemia self-corrected and was thought to be a postoperative complication related to anesthesia. She is currently followed by a glaucoma specialist. At home, she eats 2 to 3 oz of partially hydrolyzed cow milk formula every 3 hours, including overnight, an average of 101 to 151 kcal/kg per day. She has had no vomiting, diarrhea, or difficulty breathing. Her family history includes healthy parents, who both repeated a year of elementary school and received special education, and 2 healthy older brothers. Her extended family history includes a maternal grandmother who had 1 term stillbirth and 1 miscarriage and a developmentally normal 2-year-old maternal first cousin with a history of congenital cataracts. On physical examination, she is afebrile and her pulse is 152 beats/min, respiratory rate is 32 breaths/min, length is 20 in (52 cm) (2.20 percentile), weight is 3,170 g …