Tricho-hepato-enteric syndrome: Retrospective multicenter experience in Saudi Arabia.

Background: Trichohepatoenteric syndrome (THES) is a very rare disorder that is characterized by intractable congenital diarrhea, woolly hair, intrauterine growth restriction, facial dysmorphism, and short stature. Our knowledge of THES is limited due to the small number of reported cases.

Methods: Thirty patients diagnosed with THES, all molecularly confirmed by whole exome sequencing (WES) to have biallelic variants in TTC37 or SKIV2L, were included in the study. Clinical, biochemical, and nutritional phenotypes and outcome data were collected from all participants.

Results: The median age of THES patients was 3.7 years (0.9-23 years). Diarrhea and malnutrition were the most common clinical features (100%). Other common features included hair abnormalities (96%), skin hyperpigmentation (87%), facial dysmorphic abnormalities (73%), psychomotor retardation (57%), and hepatic abnormalities (30%). Twenty-five patients required parenteral nutrition (83%) with a mean duration of 13.34 months, and nearly half were eventually weaned off. Parenteral nutrition was associated with a poor prognosis. The vast majority of cases (89.6%) had biallelic variants in SKIV2L, with biallelic variants in TTC37 accounting for the remaining cases. A total of seven variants were identified in TTC37 (n = 3) and SKIV2L (n = 4). The underlying genotype influenced some phenotypic aspects, especially liver involvement, which was more common in TTC37-related THES.

Conclusion: Our data helps define the natural history of THES and provide clinical management guidelines.