Search results for "Heterozygote"
showing 10 items of 240 documents
Multiple identification of a particular type of hereditary C1q deficiency in the Turkish population: review of the cases and additional genetic and f…
1997
Complete selective deficiencies of the complement component C1q are rare genetic disorders that are associated with recurrent infections and a high prevalence of lupus erythematosus-like symptoms. All C1q deficiencies studied at the genetic level revealed single-base mutations leading to termination codons, frameshifts or amino acid exchanges and these were thought to be responsible for the defects as no other aberrations were found. One particular mutation, leading to a stop codon in the C1qA gene, was first identified in members of a Gypsy family from the Slovak Republic. The same mutation has been found in all cases of C1q deficiency from Turkey that have been investigated. Here we prese…
Compound heterozygosity in the SPG4 gene causes hereditary spastic paraplegia
2008
The SPG4 gene is frequently mutated in autosomal dominant form of hereditary spastic paraplegia (HSP). We report that the compound heterozygous sequence variants S44L, a known polymorphism, and c.1687G>A, a novel mutation in SPG4 cause a severe form of HSP in a patient. The family members carrying solely c.1687G>A mutation are asymptomatic for HSP. The reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that the c.1687G>A mutation is a splice site mutation and causes skipping of the exon 15 of spastin. Furthermore, quantification of RT-PCR products by sequencing and quantification of allele-specific expression by pyrosequencing assay revealed that c.1687G>A is a leaky…
Association between the HFE mutations and unsuccessful ageing: a study in Alzheimer's disease patients from Northern Italy
2003
Mutations in the class I-like Major Histocompatibility Complex gene HFE are associated with hereditary hemochromatosis (HH), a disorder caused by excessive iron uptake. Three common mutations have been found: C282Y, H63D, and S65C. Moreover, several studies have suggested that HFE mutations may be involved in several age-related chronic diseases such as Alzheimer's disease (AD) and coronary heart disease, but apparently paradoxically also with longevity. In particular, in AD, patients carrying the H63D allele have been suggested to have a mean age at onset of 72 vs. 77 years for those who were homozygous for the wild-type allele. Thus, it seems that H63D mutations may anticipate sporadic AD…
Genetic polymorphism and high detrimental load in natural populations of Drosophila melanogaster from cellar and vineyard
1987
Two Spanish natural populations of Drosophila melanogaster have been analysed with respect to genetic variability in third chromosome viability. The two populations, although from the same locality, belong to relatively different habitats: the inside of a cellar and a vineyard. The patterns of homozygote and heterozygote viability are similar in both populations. The homozygous detrimental loads estimated are very high and the values for the D:L (detrimental/lethal) ratio close to 2.5, which is higher than any previously found. The environmental variance of viability, average degrees of dominance of lethal genes and of viability polygenes and effective population sizes were estimated in eac…
A Single Copy of the Recently Identified Dual Oxidase Maturation Factor (DUOXA) 1 Gene Produces Only Mild Transient Hypothyroidism in a Patient with …
2011
Dual oxidases (DUOX1 and DUOX2) play a crucial role in the generation of hydrogen peroxide required in the oxidation of iodide and the synthesis of thyroid hormone. Heterodimerization with specific maturation factors (DUOXA1 and DUOXA2) is essential for the maturation and function of the DUOX enzyme complexes. Biallelic loss-of-function mutations of DUOX2 result in congenital hypothyroidism (CH), whereas a single reported case of homozygous DUOXA2 mutation (Y246X) has been associated with mild CH.We now report an infant with transient CH due to a complex genetic alteration of the DUOX/DUOXA system.Our patient was born to euthyroid nonconsanguineous parents and presented with an elevated TSH…
Goitrous Congenital Hypothyroidism and Hearing Impairment Associated with Mutations in the TPO and SLC26A4/PDS Genes
2006
Abstract Context: Pendred syndrome (PS) and thyroid peroxidase (TPO) deficiency are autosomal-recessive disorders that result in thyroid dyshormonogenesis. They share congenital hypothyroidism, goiter, and an iodide organification defect as common features. Whereas the hallmark of PS is sensorineural deafness, other forms of congenital hypothyroidism may also lead to hearing impairment. Therefore, a definite diagnosis may be difficult and require molecular genetic analyses. Case Report: The propositus presented at birth with primary hypothyroidism and goiter. He also had congenital bilateral moderate hearing loss, and PS was suspected. Methods: We sequenced the SLC26A4/PDS and TPO genes in …
Novel slow-skeletal myosin (MYH7) mutation in the original myosin storage myopathy kindred
2006
Abstract Myosin storage myopathy (OMIM 608358), a congenital myopathy characterised by subsarcolemmal, hyaline-like accumulations of myosin in Type I muscle fibres, was first described by Cancilla and Colleagues in 1971 [Neurology 1971;21:579–585] in two siblings as ‘familial myopathy with probable lysis of myofibrils in type I muscle fibres'. Two mutations in the slow skeletal myosin heavy chain gene ( MYH7 ) have recently been associated with the disease in other families. We have identified a novel heterozygous Leu1793Pro mutation in MYH7 in DNA from paraffin sections of one of the original siblings. This historical molecular analysis confirms the original cases had myosin storage myopat…
Delineation of a new chromosome 20q11.2 duplication syndrome including the ASXL1 gene.
2013
We report on three males with de novo overlapping 7.5, 9.8, and 10 Mb duplication of chromosome 20q11.2. Together with another patient previously published in the literature with overlapping 20q11 microduplication, we show that such patients display common clinical features including metopic ridging/trigonocephaly, developmental delay, epicanthal folds, and short hands. The duplication comprised the ASXL1 gene, in which de novo heterozygous nonsense or truncating mutations have recently been reported in patients with Borhing-Opitz syndrome. Because of craniofacial features in common with Borhing-Opitz syndrome, in particular metopic ridging/trigonocephaly, we suggest that duplication of ASX…
Depressive Symptoms and Alcohol Use are Genetically and Environmentally Correlated Across Adolescence
2010
Depressive symptoms and alcohol use are frequently positively associated during adolescence. This study aimed to assess the heritability of each phenotype across adolescence; to assess potential shared liabilities; to examine changes in the nature of shared liabilities across adolescence; and to investigate potential causal relationships between depressive symptoms and alcohol use. We studied a longitudinally assessed sample of adolescent Finnish twins (N = 1,282) to test hypotheses about genetic and environmental influences on these phenotypes within and across ages, using data from assessments at ages 12, 14, and 17.5 years. The heritability of depressive symptoms is consistent across ado…
H-ficolin (ficolin-3) concentrations and FCN3 gene polymorphism in neonates
2011
Serum H-ficolin (ficolin-3) concentrations (n=613) and FCN3 genotypes (n=529) from a large group of neonates are presented. Both pre-term deliveries and low birthweight (independently of gestational age) were significantly associated with low H-ficolin concentrations but not with heterozygosity for the FCN3 1637delC frameshift mutation. The presence of the variant allele, however, apparently influenced the protein level. No association of FCN3 gene heterozygosity or relative functional H-ficolin insufficiency (determined as serum level ≤8.6 μg/ml) with perinatal infections was found. One premature newborn, with confirmed infection caused by Streptococcus agalactiae, was H-ficolin-deficient …