Deficiency of Subunit 6 of the Conserved Oligomeric Golgi Complex (COG6-CDG): Second Patient, Different Phenotype

Area of Science:

• Genetics
• Immunology
• Pediatrics

Background:

• Congenital Disorders of Glycosylation (CDG) are a group of rare inherited metabolic diseases.
• COG6 deficiency, affecting subunit 6 of the COG complex, is extremely rare.
• Previous reports have not detailed the specific immunodeficiency and inflammatory bowel disease observed in this case.

Purpose of the Study:

• To describe a novel case of COG6 deficiency.
• To characterize the clinical phenotype, including multiorgan involvement and severe infections.
• To investigate the genetic basis and compare it with existing literature.

Main Methods:

• Clinical case presentation and detailed phenotypic analysis.
• Genetic mutation analysis to identify the specific COG6 gene mutation.
• Review of existing literature on COG6 deficiency and related disorders.

Main Results:

• A 27-month-old girl presented with dysmorphic features, microcephaly, and polydactyly.
• The patient exhibited chronic inflammatory bowel disease, liver cirrhosis, and recurrent life-threatening infections due to combined T-, B-cell, and neutrophil dysfunction.
• Genetic analysis revealed homozygosity for the c.G1646T mutation in the COG6 gene.

Conclusions:

• This case represents the second reported patient with COG6 deficiency and the first with associated immunodeficiency and inflammatory bowel disease.
• The distinct clinical presentation underscores the variable expressivity of COG6 mutations.
• Further research is needed to understand the complex pathophysiology of COG6 deficiency and its impact on immune and gastrointestinal systems.