Objectives: The gene encodes the α-subunit of mitochondrial processing peptidase (α-MPP), an enzyme responsible for cleavage of nuclear-encoded mitochondrial precursor proteins after their import into mitochondria. Mutations in this gene have been described in patients with nonprogressive or slow progressive cerebellar ataxia, with variable age at onset and severity. Cerebellar atrophy and striatum changes were found in severe cases.
View Article and Find Full Text PDFLittle is known about complete remission in Type 1 diabetes mellitus (T1D) with the discontinuance of insulin treatment for a period of time. In this retrospective study we analysed the frequency and factors of onset and duration of 1. remission and 2.
View Article and Find Full Text PDFBackground: Pathogenic variants in the ATAD3A gene lead to a heterogenous clinical picture and severity ranging from recessive neonatal-lethal pontocerebellar hypoplasia through milder dominant Harel-Yoon syndrome up to, again, neonatal-lethal but dominant cardiomyopathy. The genetic diagnostics of ATAD3A-related disorders is also challenging due to three paralogous genes in the ATAD3 locus, making it a difficult target for both sequencing and CNV analyses.
Results: Here we report four individuals from two families with compound heterozygous p.
Mitochondria, the cell powerhouse, are membrane-bound organelles present in the cytoplasm of almost all the eukaryotic cells. Their main function is to generate energy in the form of adenosine triphosphate (ATP). In addition, mitochondria store calcium for the cell signaling activities, generate heat, harbor pathways of intermediate metabolism and mediate cell growth and death.
View Article and Find Full Text PDFAims: We previously demonstrated that antennary fucosylated N-glycans on plasma proteins are regulated by HNF1A and can identify cases of Maturity-Onset Diabetes of the Young caused by HNF1A variants (HNF1A-MODY). Based on literature data, we further postulated that N-glycans with best diagnostic value mostly originate from alpha-1-acid glycoprotein (AGP). In this study we analyzed fucosylation of AGP in subjects with HNF1A-MODY and other types of diabetes aiming to evaluate its diagnostic potential.
View Article and Find Full Text PDFBackground: Isolated methylmalonic aciduria can be caused by pathogenic mutations in the gene for methylmalonyl-CoA mutase or in the genes encoding enzymes involved in the intracellular metabolism of cobalamin. Some of these mutations may be cobalamin responsive. The type of methylmalonic aciduria cannot always be assumed from clinical manifestation and the responsiveness to cobalamin has to be assessed for appropriate cobalamin administration, or to avoid unnecessary treatment.
View Article and Find Full Text PDFThe genetic heterogeneity of sensorineural hearing loss (SNHL) is a major hurdle to the detection of disease-causing variants. We aimed to identify underlying causal genes associated with mid-frequency hearing loss (HL), which contributes to less than about 1% of SNHL cases, by whole exome sequencing (WES). Thirty families segregating mid-frequency SNHL, in whom biallelic GJB2 mutations had been previously excluded, were selected from among 851 families in our DNA repository of SNHL.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
December 2021
Aim: Afamin is a liver-produced glycoprotein, a potential early marker of metabolic syndrome. Here we investigated regulation of afamin in a course of the metabolic disease development and in response to 3-month exercise intervention.
Methods: We measured whole-body insulin sensitivity (euglycemic hyperinsulinemic clamp), glucose tolerance, abdominal adiposity, hepatic lipid content (magnetic resonance imaging/spectroscopy), habitual physical activity (accelerometers) and serum afamin (enzyme-linked immunosorbent assay) in 71 middle-aged men with obesity, prediabetes and newly diagnosed type 2 diabetes.
Hearing loss is a genetically heterogeneous sensory defect, and the frequent causes are biallelic pathogenic variants in the gene. However, patients carrying only one heterozygous pathogenic (monoallelic) variant represent a long-lasting diagnostic problem. Interestingly, previous results showed that individuals with a heterozygous pathogenic variant are two times more prevalent among those with hearing loss compared to normal-hearing individuals.
View Article and Find Full Text PDFMutations of the gene are the most common cause of the permanent neonatal diabetes mellitus (PNDM). Majority of people with KNCJ11-PNDM have a de-novo mutation. We aimed to compare diabetes phenotype in two children and their mothers with PNDM carrying the same sulfonylurea-sensitive variants.
View Article and Find Full Text PDFInt J Pediatr Otorhinolaryngol
January 2021
Waardenburg syndrome (WS) is a clinically and genetically heterogeneous group of inherited disorders manifesting with sensorineural hearing loss and pigmentary anomalies. Here we present two Caucasian families with novel variants in EDNRB and SOX10 representing both sides of phenotype spectrum in WS. The c.
View Article and Find Full Text PDFOrphanet J Rare Dis
August 2020
Background: The Roma are a European ethnic minority threatened by several recessive diseases. Variants in MANBA cause a rare lysosomal storage disorder named beta-mannosidosis whose clinical manifestation includes deafness and mental retardation. Since 1986, only 23 patients with beta-mannosidosis and biallelic MANBA variants have been described worldwide.
View Article and Find Full Text PDFMODY (Maturity Onset Diabetes of the Young) is a type of diabetes resulting from a pathogenic effect of gene mutations. Up to date, 13 MODY genes are known. Gene HNF1A is one of the most common causes of MODY diabetes (HNF1A-MODY; MODY3).
View Article and Find Full Text PDFBackground: Progressive bilateral sensorineural deafness in postlingual period may be linked to many different etiologies including genetic factors. Identification of the exact deafness cause may, therefore, be quite challenging. Here we present a family with late-onset hearing loss as an autosomal dominant trait caused by a novel EYA4 mutation.
View Article and Find Full Text PDFImpairment of saposin B causes rare atypical metachromatic leukodystrophy (MLD). It is encoded (together with saposin A, C, and D) by the PSAP gene. Only ten pathogenic variants were described in the PSAP gene in MLD patients to date.
View Article and Find Full Text PDFContext: Leptin secreted from adipose tissue signals peripheral energy status to the brain. Monogenic leptin deficiency results in severe early onset obesity with hyperphagia. Recently, a similar phenotype of inactivating leptin mutations but with preserved immunoreactivity and hence normal circulating immunoreactive leptin has been reported.
View Article and Find Full Text PDFBackground: Inactivating mutations of the hypothalamic transcription factor singleminded1 (SIM1) have been shown as a cause of early-onset severe obesity. However, to date, the contribution of SIM1 mutations to the obesity phenotype has only been studied in a few populations. In this study, we screened the functional regions of SIM1 in severely obese children of Slovak and Moravian descent to determine if genetic variants within SIM1 may influence the development of obesity in these populations.
View Article and Find Full Text PDFAim: Congenital hyperinsulinism (CHI) and glycogen storage disease (glycogenosis) are both causing hypoglycemia during infancy, but with different additional clinical features and therapeutic approach. We aimed to identify a genetic cause in a child with an ambiguous phenotype.
Methods And Results: We present a child with hyperinsulinemic hypoglycemia, physiological 3-OH butyrate, increased triglyceride serum levels, increased level of glycogen in erythrocytes, increased liver transaminases, and increased echogenicity on liver ultrasonography.
Impairment of translation initiation and its regulation within the integrated stress response (ISR) and related unfolded-protein response has been identified as a cause of several multisystemic syndromes. Here, we link MEHMO syndrome, whose genetic etiology was unknown, to this group of disorders. MEHMO is a rare X-linked syndrome characterized by profound intellectual disability, epilepsy, hypogonadism and hypogenitalism, microcephaly, and obesity.
View Article and Find Full Text PDFCongenital hyperinsulinism (CHI) is the most common cause of severe persistent hypoglycemia in neonates and infants. Early diagnosis and effective treatment (based on the principles of pharmacogenetics) play the key role for the prognosis. The DNA anlysis, which can identify mutation in one of the 11 genes causing MODY, is crutial in the diagnostics.
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