OBJECTIVE: To analyze the clinical presentation and gene of 2 pedigrees with suspected oculocutaneous albinism(OCA), and provide basis for clinical classification, genetic counseling and prenatal diagnosis. METHODS: Variants were identified using next-generation sequencing(NGS) and confirmed by Sanger sequencing in 2 pedigrees with suspected OCA. The pathogenicity of the variants was analyzed according to the American College of Medical Genetics and Genomics (ACMG) standard. RESULTS: Two compound heterozygous mutations of TYR and OCA2 genes were identified respectively in 2 pedigrees with suspected OCA. The mutation of c.819+3insATATGCC in TYR and the mutation of c.1870G>C in OCA2 are first reported in this study. The pathogenicity analysis shows that two novel mutations are likely pathogenic by combination of prediction of SIFT, Polyphen-2 and Human Splicing Finder. CONCLUSION The findings of this study expand the mutational spectrum of OCA. Compound heterozygous mutations in the TYR and OCA2 gene may be responsible for clinical manifestations of 2 pedigrees with suspected OCA.
Albinism, Oculocutaneous ; DNA Mutational Analysis ; Female ; High-Throughput Nucleotide Sequencing ; Humans ; Membrane Transport Proteins ; Monophenol Monooxygenase ; Mutation ; Pedigree ; Pregnancy

Objective:To investigate the clinical phenotype and genotype characteristics of lipoyltransferase 1 deficiency (LIPT1D).Methods:A retrospective analysis of the clinical data was conducted for one case of LIPT1D, admitted to the Department of Neonatology at Shanghai Children's Hospital on May 7, 2023. Key terms "lipoyltransferase 1 deficiency", " LIPT1", and "lipoic acid" were used to search national databases including CNKI, Wanfang Data, VIP, and Yiigle; and international databases PubMed, Embase, and Web of Science until September 15, 2023, to summarize the clinical presentations, biochemical phenotypes, and genotypic characteristics of LIPT1D. Descriptive statistical analysis was employed. Results:(1) The case concerned: At 1.5 h after birth, the infant exhibited cyanosis and poor responsiveness, presenting with uncorrectable metabolic acidosis (blood pH value 6.9, base excess -27 mmol/L, bicarbonate 5.7 mmol/L), and hyperlactatemia (the highest was 24 mmol/L). The condition progressed rapidly, and the infant died 9 h after birth. Whole exome sequencing performed 6 h postnatally identified compound heterozygous variants in the LIPT1 gene (NM_001204830.1) in the infant. Variants c.986C>A (p.Ser329*) from the mother and c.405_406del (p.Arg135Serfs*18) from the father were detected, both suspected to be pathogenic. (2) Literature review: A review of the literature identified seven cases of LIPT1D caused by LIPT1 gene mutations, totaling eight cases including the current one. The main presentations of LIPT1D in these infants were hyperlactatemia, metabolic acidosis, neurodevelopmental delay, and epilepsy, with four cases presenting in the neonatal period and resulting in death. Conclusions:The primary clinical manifestations of LIPT1D are severe hyperlactatemia, metabolic acidosis, and neurological involvement, potentially leading to early neonatal death. Whole-exome sequencing is instrumental in diagnosing this condition.

Objective To explore the pathogenesis of Russell-Silver syndrome (RSS). Methods Two milliliter peripheral blood samples were collected from 6 male patients aged 6 to 8 years with suspected RSS phenotype, the parents of 2 patients and 5 healthy boys. Mononuclear cells were isolated and genomic DNA was extracted. The methylation level of the H19 imprinting control region(ICR)1 on chromosome 11p15.5 was detected by pyrosequencing.The methylation status and the copy number variation in the corresponding region of one RSS patient with positive results by pyrosequencing were analysed by methylation-specific multiplex-ligation-dependent probe amplification assay (MS-MLPA). Results Pyrosequencing analysis revealed that the methylation rates on the 6 CpG targeting sites in H19 differentially methylated region(DMR)in the 6 RSS patients were about 11%~29%, which were significantly lower than those in their parents and normal controls (44%~59%). The MS-MLPA results of one patient with positive pyrosequencing showed that the methylation rates of 4 sites in H19-DMR were about 10%,which was obviously lower than the normal level.The methylation rates of the 4 sites in KCNQ1OT1 gene were about 50%, which was in the normal range. The copy number variations from all samples detected were in the normal range. Conclusion There is methylation aberration of H19-DMR in ICR1 in children with RSS.