RESUMEN
Congenital neutropenia syndromes encompass a group of genetic disorders characterized by persistent neutropenia and recurrent infections inherited in an autosomal recessive, dominant, or X-linked manner. These syndromes arise from mutations in various genes, and one of the significant genes involved is glucose-6-phosphatase catalytic subunit 3 (G6PC3), giving rise to a condition known as Dursun syndrome. As per existing knowledge, a total of 92 cases of Dursun syndrome have been reported globally, including eight cases from Saudi Arabia. Our study identified two additional cases exhibiting neutropenia since the early postnatal period and recurrent admissions due to infections. Additionally, these patients presented with oral ulcers, chronic diarrhea, and anomalies affecting the cardiac and genitourinary systems. The rising incidence of congenital neutropenia on a global scale necessitates heightened vigilance among clinicians to ensure thorough follow-up of patients with neutropenia. This proactive approach can lead to early detection and appropriate management of associated complications, ultimately improving patient outcomes.
RESUMEN
Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency is an inherited metabolic disease caused by mutated OXCT1 gene resulting in recurrent ketoacidosis. Analysis of longitudinal data in such an ultra-rare disease is warranted to delineate genotype-phenotype correlations and management outcome. A retrospective analysis of 17 patients, from nine unrelated families, with SCOT deficiency who were followed up in the Medical Genetics Clinic at King Faisal Specialist Hospital and Research Centre was conducted. All the patients were homozygous for p.R468C in OXCT1 gene. Most of the patients (n = 15, 88.2%) were symptomatic presenting with recurrent ketoacidosis, the onset of which ranged from 6 months to 4 years (median 2 years). A striking inter- and intrafamilial variability that ranged from being entirely asymptomatic to death during the first episode. All patients were instructed to avoid fasting, restrict protein in diet, and receive carnitine supplementation. However, there was no correlation between following instructions of chronic management and outcome. Most of the patients had their crises resolved and all of them had normal neurodevelopmental outcome. Our data suggest that SCOT deficiency caused by homozygous p.R468C has variable clinical presentation and incomplete penetrance. The apparent lack of correlation between protein restriction +/- carnitine supplementation and outcome suggests that chronic dietary restriction may not be warranted. However, a longer follow-up on larger and heterogenous cohort of cases is needed before a clear conclusion on the long-term management can be reached.
