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Abstract Background This study aimed to investigate the clinical and molecular genetic characteristics of ten children with ornithine carbamoyltransferase deficiency (OTCD) in southeastern China, as well as the correlation between the genotype and phenotype of OTCD. Methods A retrospective analysis was performed on the clinical manifestations, laboratory testing, and genetic test findings of ten children with OTCD admitted between August 2015 and October 2021 at Quanzhou Maternity and Children’s Hospital of Fujian Province in China. Results Five boys presented with early-onset symptoms, including poor appetite, drowsiness, groaning, seizures, and liver failure. In contrast, five patients (one boy and four girls) had late-onset gastrointestinal symptoms as the primary clinical manifestation, all presenting with hepatic impairment, and four with hepatic failure.Nine distinct variants of the OTC gene were identified, including two novel mutations: c.1033del(p.Y345Tfs*50) and c.167T > A(p.M56K). Of seven patients who died, five had early-onset disease despite active treatment. Three patients survived, and two of them underwent liver transplantation. Conclusions The clinical manifestations of OTCD lack specificity. However, elevated blood ammonia levels serve as a crucial diagnostic clue for OTCD. Genetic testing aids in more accurate diagnosis and prognosis assessment by clinicians. In addition, we identified two novel pathogenic variants and expand the mutational spectrum of the gene OTC, which may contribute to a better understanding of the clinical and genetic characteristics of OTCD patients.

This article reports the characterization of two siblings diagnosed with late-onset multiple Acyl-CoA dehydrogenase deficiency (MADD) caused by mutations in electron transfer flavoprotein(ETF)-ubiquinone oxidoreductase (ETF-QO) (ETFDH) gene. Whole exome sequencing (WES) was performed in the proband's pedigree. Clinical phenotypes of Proband 1 (acidosis, hypoglycemia, hypotonia, muscle weakness, vomiting, hypoglycemia, hepatomegaly, glutaric acidemia, and glutaric aciduria) were consistent with symptoms of MADD caused by the ETFDH mutation. However, Proband 2 presented with only a short stature. The patients (exhibiting Probands 1 and 2) showed identical elevations of C6, C8, C10, C12, and C14:1. c.1842_1845 (exon13)dup, and c.250 (exon3) G > A of the ETFDH gene were compound heterozygous variants in both patients. The novel variant c.1842_1845dup was rated as likely pathogenic according to the American College of Medical Genetics and Genomics guidelines (ACMG). This is the first report on the c.1842_1845dup mutation of the ETFDH gene in patients with late-onset MADD, and the data described herein may help expand the mutation spectrum of ETFDH.

Abstract Background Central precocious puberty (CPP) is a precocious puberty due to premature activation of the hypothalamic–pituitary‐gonadal axis (HPG). MKRN3 defects are well‐known causes of CPP, while DLK1 mutations were recently identified in a few patients with CPP. Methods The study was approved by the Institutional Review and the scientific committee of the hospital. The clinical data were collected. Whole‐exome sequencing (WES) was performed to detect causative variants. Key words ‘DLK1’, ‘MKRN3’, and “central precocious puberty” were used for literature search in PubMed, Google Scholar, HGMD, and OMIM databases. Results The patient, a male, whose puberty began before age nine, had significant metabolic abnormalities including overweight, hyperlipidemia, and hyperuricemia. WES detected a recurrent frame‐shift mutation, NM_003836.5:c.479delC(p.P160fs*50) in DLK1 in the patient and his father. Conclusion The familial DLK1‐CPP was identified in China for the first time, which supported that short stature is predicted in patients with CPP without GnRHa treatment. Therefore, we recommend that children with DLK1‐CPP should be treated as early as possible to improve adult height. The patient in this study had persistent hyperuricemia, further suggests that this antiadipogenic factor represents a link between reproduction and metabolism.

Abstract Background Holocarboxylase synthetase (HLCS) deficiency is a rare inborn disorder of biotin metabolism, which results in defects in several biotin-dependent carboxylases and presents with metabolic ketoacidosis and skin lesions. Case presentation In this paper, we report a Chinese Han pedigree with HLCS deficiency diagnosed by using next-generation sequencing and validated with Sanger sequencing of the HLCS and BTD genes. The Chinese proband carries the common missense mutation c.1522C > T (p.Arg508Trp) in exon 9 of the HLCS gene, which generates an increased K m value for biotin. A novel frameshift mutation c.1006_1007delGA (p.Glu336Thrfs*15) in exon 6 of the HLCS gene is predicted to be deleterious through PROVEAN and MutationTaster. A novel heterozygous mutation, c.638_642delAACAC (p.His213Profs*4), in the BTD gene is also identified. Conclusions The Chinese proband carries the reported Arg508Trp variant, the novel 2-bp frameshift mutation c.1006_1007delGA (p.Glu336Thrfs*15), which expands the mutational spectrum of the HLCS gene, and the novel heterozygous mutation c.638_642delAACAC (p.His213Profs*4), which expands the mutational spectrum of the BTD gene. Furthermore, reversible hearing damage is rarely reported in patients with HLCS deficiency, which deserves further discussion.