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GYG2 and Leigh Syndrome

In this report, two affected male siblings with Leigh syndrome were found to carry a hemizygous missense mutation in GYG2, supporting an X‑linked recessive inheritance pattern (PMID:24100632). The variant, c.665G>C (p.Trp222Ser), was identified via whole exome sequencing and segregated with disease in this single family. Clinical findings in the siblings, including progressive neurodegeneration and metabolic abnormalities, align with the typical features of Leigh syndrome. Although the cohort is limited to one family, the genetic data offer preliminary support for an association between GYG2 and Leigh syndrome.

Functional evidence further reinforces the potential pathogenicity of this variant. In vitro assays demonstrated that the mutant GYG2 protein fails to perform self‑glucosylation, while in silico structural modeling predicted significant destabilization of the protein, consistent with the observed biochemical abnormality (PMID:24100632). Together, the genetic and experimental data imply that GYG2 dysfunction may contribute to the development of Leigh syndrome. Key take‑home: Despite limited patient numbers, integrating segregation analysis with supportive functional assays provides clinically useful evidence for considering GYG2 in the diagnostic workup of Leigh syndrome.

References

  • Human Genetics • 2014 • A hemizygous GYG2 mutation and Leigh syndrome: a possible link? PMID:24100632

Evidence Based Scoring (AI generated)

Gene–Disease Association

Limited

One family comprising two affected siblings with a hemizygous missense mutation provides preliminary evidence, although the cohort size is limited (PMID:24100632).

Genetic Evidence

Limited

The identification of the c.665G>C (p.Trp222Ser) variant in two male siblings with concordant clinical features supports a genetic association in a limited familial context (PMID:24100632).

Functional Evidence

Moderate

In vitro functional assays showed that the mutant GYG2 lacks self‑glucosylation activity and structural modeling predicts instability, thereby bolstering the evidence for a deleterious effect (PMID:24100632).