Detection of GCDH mutations in five Chinese patients with glutaric acidemia type I / 中华医学遗传学杂志

OBJECTIVE To detect potential mutations of GCDH gene in five patients with glutaric acidemia type I (GA-I). METHODS Genomic DNA was extracted from peripheral blood samples from the patients. The 11 exons and their flanking sequences of the GCDH gene were amplified with PCR and subjected to direct sequencing. RESULTS Four mutations of the GCDH gene were identified among the patients, which included c.532G>A (p.G178R), c.533G>A (p.G178E), c.106_107delAC (p.Q37fs*5) and c.1244-2A>C. Among these, c.1244-2A>C was the most common, while c.106_107delAC was a novel mutation, which was predicted to be pathogenic by MutationTaster software. CONCLUSION The diagnosis of GA-I has been confirmed in all of the five patients. Identification of the novel GCDH mutations has enriched the mutational spectrum of the GCDH gene.

Mutational analysis of SLC22A5 gene in eight patients with systemic primary carnitine deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the mutations of SLC22A5 gene in patients with systemic primary carnitine deficiency (CDSP).</p><p><b>METHODS</b>High liquid chromatography tandem mass spectrometry (HPLC/MS/MS) was applied to screen congenital genetic metabolic disease and eight patients with CDSP were diagnosed among 77 511 samples. The SLC22A5 gene mutation was detected using massarray technology and sanger sequencing. Using SIFT and PolyPhen-2 to predict the function of protein for novel variations.</p><p><b>RESULTS</b>Total detection rate of gene mutation is 100% in the eight patients with CDSP. Seven patients had compound heterozygous mutations and one patient had homozygous mutations. Six different mutations were identified, including one nonsense mutation [c.760C>T(p.R254X)] and five missense mutations[c.51C>G(p.F17L), c.250T>A(p.Y84N), c.1195C>T(p.R399W), c.1196G>A(p.R399Q), c.1400C>G(p.S467C)]. The c.250T>A(p.Y84N) was a novel variation, the novel variation was predicted to have affected protein structure and function. The c.760C>T (p.R254X)was the most frequently seen mutation, which was followed by the c.1400C>G(p.S467C).</p><p><b>CONCLUSION</b>This study confirmed the diagnosis of eight patients with CDSP on the gene level. Six mutations were found in the SLC22A5 gene, including one novel mutation which expanded the mutational spectrum of the SLC22A5 gene.</p>

Mutational analysis of ASS1, ASL and SLC25A13 genes in six Chinese patients with citrullinemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect potential mutations in six patients with citrullinemia.</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood samples from the patients. Mutations of the ASS1, ASL and SLC25A13 genes were screened using microarray genotyping combined with direct sequencing.</p><p><b>RESULTS</b>One patient was diagnosed with argininosuccinate lyase deficiency, and has carried a homozygous c.1311T>G (p.Y437*) mutation of the ASL gene. The remaining five patients were diagnosed with neonatal intrahepatic cholestasis due to citrin deficiency, and have respectively carried mutations of the SLC25A13 gene including [c.851-854delGTAT+c.851-854delGTAT], [c.851-854delGTAT+IVS6+5G>A], [c.851-854delGTAT+IVS16ins3kb], [c.851-854delGTAT+IVS6-11A>G] and [c.851-854delGTAT+c.1638-1660dup23]. Among these, the c.1311T>G mutation was first identified in the Chinese population, and the IVS6-11A>G mutation was a novel variation which may affect the splicing, as predicted by Human Splicing Finder software.</p><p><b>CONCLUSION</b>This study has confirmed the molecular diagnosis of citrullinemia in six patients and expanded the mutational spectrum underlying citrullinemia.</p>