Introduction: Prohormone convertases are a family of proteins that mediate the processing and activation of peptide hormones and neuropeptide precursors. Homozygous mutations of the PCSK1 gene result in prohormone convertase 1 deficiency that is characterized by diarrhea, hypoglycemia, multiple pituitary hormone deficiency beginning from neonatal period and obesity beginning after infancy.
Case: A 35-day-old boy was referred to our hospital with hypoglycemia and metabolic acidosis. He was born 3400 grams at term; received phototherapy with indirect hyperbilirubinemia at the age of 3 days; readmitted with deterioration in general condition, dehydration, hypoglycemia, metabolic acidosis and hyperbilirubinemia at the age of 13 days; recovered after blood exchange, fluid and inotrop therapy but metabolic acidosis and hypoglycemia repeated after refeeding. Parents had 4th degree consanguinity and his mothers cousin who died at the age of 18 months had homozygous PCSK1 mutation. His body weight was 3280 g (-1.82 SD), height was 51 cm (-1.3 SD), and physical examination was normal except for hypotonicity at admission. His pituitary functions were evaluated with the pre-diagnosis of prohormone convertase deficiency and hydrocortisone treatment was initiated after detecting low cortisol levels. In the follow up diarrhea began after the first month and his diet was arranged with Basic-CH formula and pancreatin treatment. A likely pathogenic homozygous change, NM_000439.5 c: 635G> A (p.Cys212Tyr) was detected in the PCSK1 gene whole gene sequence analysis.
Conclusion: In the presence of hypoglycemia and metabolic acidosis in the newborn and infant period; in case diarrhea is added; prohormone convertase deficiency should be considered in the differential diagnosis.
22 Sep 2021 - 26 Sep 2021