Proprotein Convertase 1/3 Deficiency

Excerpt

To the Editor: Congenital diarrheal disorders (CDD’s) are a rare entity caused by various recessively inherited mutations and typically manifest in early stages of life [1]. Proprotein convertase subtilisin/kexin type 1 (PCSK1) gene encodes for prohormone convertase 1/3 (PC1/3) responsible for peptide hormone processing within the enteroendocrine cell [2]. This enzyme activates multiple substrates including proglucagon, pro-insulin, and propiomelanocortin to their active metabolites [3]. PC1/3 deficiency leads to severe watery diarrhea, impaired growth in infantile period, and severe obesity and endocrinopathies e.g., Growth Hormone (GH) deficiency, Diabetes Insipidus (DI) and hypogonadism if children survive the neonatal period [3]. We report two siblings who presented with severe diarrhea in the neonatal period and summarize their clinical features outlining the importance of early diagnosis and intervention (Table 1). …