Nafiye Emel Çakar1, Alper Gezdirici2, Hanım Şeyma Topuz3, Hasan Önal3. 1. Division of Pediatric Metabolism, Okmeydanı Training and Research Hospital, University of Health Sciences, İstanbul, Turkey. 2. Division of Medical Genetics, Kanuni Sultan Süleyman Training and Research Hospital, University of Health Sciences, İstanbul, Turkey. 3. Division of Pediatric Metabolism, Kanuni Sultan Süleyman Training and Research Hospital, University of Health Sciences, İstanbul, Turkey.
Abstract
BACKGROUND: Glycogen storage diseases (GSD) are disorders of autosomal recessive carbohydrate metabolism, characterized by glycogen accumulation. The liver and muscle tissue are commonly affected but patients may present with different clinical manifestations. The presence of glycogen can be demonstrated in biopsies and definitive diagnosis can be made by enzymatic or molecular analysis. The aim of this study was to determine specific gene mutations in our cases with GSD. METHODS: Thirty-eight patients with clinical and laboratory diagnoses of GSD were studied. Thirty-two patients had undergone genetic analysis. In our study, a next-generation sequencing panel was used. RESULTS: Five novel variants of uncertain significance (VUS), which were likely to be pathogenic, were detected in seven patients. Two new pathogenic variations of c.927delT (p.Phe309LeufsTer4) homozygous and c.44C>G (p.Ser15Ter) homozygous in the G6PC gene were detected in two GSD type Ia patients. In our two non-sibling GSD type III patients, c.1439T>G (p.Leu480Arg) homozygous novel-VUS was detected in the AGL gene. In our GSD type IV patient, c.1054G>C (p.Asp352His) homozygous novel-VUS was detected in the GBE1 gene. In GSD type VI, two sibling patients had a c.1454A>G (p.Asn485Ser) homozygous novel-VUS change in the PYGL gene. CONCLUSIONS: We determined the gene mutations specific to cohorts in our cases with GSD. The novel pathogenic, likely pathogenic, and VUS changes identified will contribute to the relationship between the patients' clinical and laboratory findings.
BACKGROUND: Glycogen storage diseases (GSD) are disorders of autosomal recessive carbohydrate metabolism, characterized by glycogen accumulation. The liver and muscle tissue are commonly affected but patients may present with different clinical manifestations. The presence of glycogen can be demonstrated in biopsies and definitive diagnosis can be made by enzymatic or molecular analysis. The aim of this study was to determine specific gene mutations in our cases with GSD. METHODS: Thirty-eight patients with clinical and laboratory diagnoses of GSD were studied. Thirty-two patients had undergone genetic analysis. In our study, a next-generation sequencing panel was used. RESULTS: Five novel variants of uncertain significance (VUS), which were likely to be pathogenic, were detected in seven patients. Two new pathogenic variations of c.927delT (p.Phe309LeufsTer4) homozygous and c.44C>G (p.Ser15Ter) homozygous in the G6PC gene were detected in two GSD type Iapatients. In our two non-sibling GSD type III patients, c.1439T>G (p.Leu480Arg) homozygous novel-VUS was detected in the AGL gene. In our GSD type IV patient, c.1054G>C (p.Asp352His) homozygous novel-VUS was detected in the GBE1 gene. In GSD type VI, two sibling patients had a c.1454A>G (p.Asn485Ser) homozygous novel-VUS change in the PYGL gene. CONCLUSIONS: We determined the gene mutations specific to cohorts in our cases with GSD. The novel pathogenic, likely pathogenic, and VUS changes identified will contribute to the relationship between the patients' clinical and laboratory findings.