A Turkish trichothiodystrophy patient with homozygous XPD mutation and genotype-phenotype relationship.

Trichothiodystrophy (TTD) is a rare, recessive condition involving multiple organs and systems. Four genes associated with nuclear excision repair have been described in the molecular etiology of TTD. There is a significant heterogeneity of clinical and laboratory findings of TTD, even in individuals carrying the same mutation.

Presence of ATM protein and residual kinase activity correlates with the phenotype in ataxia-telangiectasia: a genotype-phenotype study.

Ataxia-telangiectasia (A-T) is an autosomal recessive neurodegenerative disorder with multisystem involvement and cancer predisposition, caused by mutations in the A-T mutated (ATM) gene. To study genotype-phenotype correlations, we evaluated the clinical and laboratory data of 51 genetically proven A-T patients, and additionally measured ATM protein expression and kinase activity. Patients without ATM kinase activity showed the classical phenotype.

A novel mutation F826L in the human androgen receptor in partial androgen insensitivity syndrome; increased NH2-/COOH-terminal domain interaction and TIF2 co-activation.

A novel mutation F826L located within the ligand binding domain (LBD) of the human androgen receptor (AR) was investigated. This mutation was found in a boy with severe penoscrotal hypospadias (classified as 46,XY DSD). The AR mutant F826L appeared to be indistinguishable from the wild-type AR, with respect to ligand binding affinity, transcriptional activation of MMTV-luciferase and ARE2-TATA-luciferase reporter genes, protein level in genital skin fibroblasts (GSFs), and sub-cellular distribution in transfected cells.

Incidence of DNA repair deficiency disorders in western Europe: Xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy.

Laboratory diagnosis for DNA repair diseases has been performed in western Europe from the early seventies for xeroderma pigmentosum (XP) and from the mid-eighties for Cockayne syndrome (CS) and trichothiodystrophy (TTD). The combined data from the DNA repair diagnostic centres in France, (West) Germany, Italy, the Netherlands and the United Kingdom have been investigated for three groups of diseases: XP (including XP-variant), CS (including XP/CS complex) and TTD. Incidences in western Europe were for the first time established at 2.

Prenatal diagnosis of xeroderma pigmentosum and trichothiodystrophy in 76 pregnancies at risk.

Objective: Evaluation of results in a consecutive series of 76 prenatal diagnoses for xeroderma pigmentosum (XP) and trichothiodystrophy (TTD) made since 1977.

Methods: UV-induced DNA repair synthesis was assessed by the autoradiographic measurement of the incorporation of (3)H-thymidine.

Results: XP was diagnosed in 19 of the 76 investigated pregnancies at risk; cultured chorionic villus (CV) cells were used in 33 pregnancies with ten affected fetuses and cultured amniocytes in 43 pregnancies with nine affected fetuses.

First reported patient with human ERCC1 deficiency has cerebro-oculo-facio-skeletal syndrome with a mild defect in nucleotide excision repair and severe developmental failure.

Nucleotide excision repair (NER) is a genome caretaker mechanism responsible for removing helix-distorting DNA lesions, most notably ultraviolet photodimers. Inherited defects in NER result in profound photosensitivity and the cancer-prone syndrome xeroderma pigmentosum (XP) or two progeroid syndromes: Cockayne and trichothiodystrophy syndromes. The heterodimer ERCC1-XPF is one of two endonucleases required for NER.

GM1 gangliosidosis: molecular analysis of nine patients and development of an RT-PCR assay for GLB1 gene expression profiling.

The human GLB1 gene produces two alternatively spliced transcripts that encode the lysosomal enzyme beta-galactosidase (GLB1) and the elastin binding protein (EBP). Mutations at the GLB1 locus, which are responsible for the storage disorder GM1 gangliosidosis, may affect either both proteins or GLB1 only. The EBP, when affected, contributes to specific features of GM1 gangliosidosis patients, such as cardiomyopathy and connective-tissue abnormalities.

A new progeroid syndrome reveals that genotoxic stress suppresses the somatotroph axis.

XPF-ERCC1 endonuclease is required for repair of helix-distorting DNA lesions and cytotoxic DNA interstrand crosslinks. Mild mutations in XPF cause the cancer-prone syndrome xeroderma pigmentosum. A patient presented with a severe XPF mutation leading to profound crosslink sensitivity and dramatic progeroid symptoms.

Mutations in the C7orf11 (TTDN1) gene in six nonphotosensitive trichothiodystrophy patients: no obvious genotype-phenotype relationships.

Trichothiodystrophy (TTD) is a rare autosomal recessive disorder whose defining feature is brittle hair. Associated clinical symptoms include physical and mental retardation of different severity, ichthyosis, premature aging, and, in half of the patients, photosensitivity. Recently, C7orf11 (TTDN1) was identified as the first disease gene for the nonphotosensitive form of TTD, being mutated in two unrelated cases and in an Amish kindred.

Prenatal diagnosis of the Cockayne syndrome: survey of 15 years experience.

Objective: Evaluation of results in a consecutive series of 29 prenatal diagnoses for the Cockayne syndrome.

Methods: Recovery of DNA-synthesis in UV-irradiated cultured fetal cells was measured by scintillation counting of incorporated (3)H-thymidine. Semiquantitative autoradiographic assessment of the recovery of RNA-synthesis (RecRS) was used as an adjunctive method.

The cystathionine beta-synthase variant c.844_845ins68 protects against CNS demyelination in X-linked adrenoleukodystrophy.

The clinical course of X-linked adrenoleukodystrophy (X-ALD) is of unexplained heterogeneity. Major X-ALD phenotypes are the progressive childhood cerebral form (CCALD) with early confluent cerebral demyelination and the adult-onset adrenomyeloneuropathy (AMN). Adult AMN may present with demyelinated foci of the CNS (adrenoleukomyeloneuropathy, ALMN) or without ("pure" AMN).

Senescence-associated beta-galactosidase is lysosomal beta-galactosidase.

Replicative senescence limits the proliferation of somatic cells passaged in culture and may reflect cellular aging in vivo. The most widely used biomarker for senescent and aging cells is senescence-associated beta-galactosidase (SA-beta-gal), which is defined as beta-galactosidase activity detectable at pH 6.0 in senescent cells, but the origin of SA-beta-gal and its cellular roles in senescence are not known.

Prenatal diagnosis of citrullinemia and argininosuccinic aciduria: evidence for a transmission ratio distortion in citrullinemia.

Background: In the course of 25 years, we have experienced a high rate of affected fetuses in the prenatal diagnosis of citrullinemia.

Methods And Results: Ninety-one pregnancies at 1 in 4 risk were tested; 36 were diagnosed as affected (39.5%; P = 0.

Loss of ZMPSTE24 (FACE-1) causes autosomal recessive restrictive dermopathy and accumulation of Lamin A precursors.

Restrictive dermopathy (RD) is characterized by intrauterine growth retardation, tight and rigid skin with prominent superficial vessels, bone mineralization defects, dysplastic clavicles, arthrogryposis and early neonatal death. In two patients affected with RD, we recently reported two different heterozygous splicing mutations in the LMNA gene, leading to the production and accumulation of truncated Prelamin A. In other patients, a single nucleotide insertion was identified in ZMPSTE24.

Functional analysis of a novel androgen receptor mutation, Q902K, in an individual with partial androgen insensitivity.

Androgen insensitivity syndrome (AIS) is caused by defects in the androgen receptor (AR) that render the AR partially or completely inactive. As a result, embryonic sex differentiation is impaired. Here, we describe a novel mutation in the AR found in a patient with partial AIS.

Molecular and functional analysis of SUMF1 mutations in multiple sulfatase deficiency.

Multiple sulfatase deficiency (MSD) is a rare disorder characterized by impaired activity of all known sulfatases. The gene mutated in this disease is SUMF1, which encodes a protein involved in a post-translational modification at the catalytic site of all sulfatases that is necessary for their function. SUMF1 strongly enhances the activity of sulfatases when coexpressed with sulfatase in Cos-7 cells.

Twenty-two novel mutations in the lysosomal alpha-glucosidase gene (GAA) underscore the genotype-phenotype correlation in glycogen storage disease type II.

Patients with glycogen storage disease type II (GSDII, Pompe disease) suffer from progressive muscle weakness due to acid alpha-glucosidase deficiency. The disease is inherited as an autosomal recessive trait with a spectrum of clinical phenotypes. We have investigated 29 cases of GSDII and thereby identified 55 pathogenic mutations of the acid alpha-glucosidase gene (GAA) encoding acid maltase.

Mutations in the gene encoding capillary morphogenesis protein 2 cause juvenile hyaline fibromatosis and infantile systemic hyalinosis.

Juvenile hyaline fibromatosis (JHF) and infantile systemic hyalinosis (ISH) are autosomal recessive conditions characterized by multiple subcutaneous skin nodules, gingival hypertrophy, joint contractures, and hyaline deposition. We previously mapped the gene for JHF to chromosome 4q21. We now report the identification of 15 different mutations in the gene encoding capillary morphogenesis protein 2 (CMG2) in 17 families with JHF or ISH.

Identification and functional assessment of novel and known insulin receptor mutations in five patients with syndromes of severe insulin resistance.

We analyzed the insulin receptor gene in four patients with leprechaunism and one with type A insulin resistance. We detected novel and previously reported mutations. The novel mutants were expressed in Chinese hamster ovary cells to evaluate the consequences for insulin receptor function.

Variable clinical presentation of lysosomal beta-mannosidosis in patients with null mutations.

Beta-mannosidosis is an autosomal recessive lysosomal storage disease resulting from a deficiency of the lysosomal enzyme beta-mannosidase. The clinical manifestations of this disease in reported human cases are very heterogeneous ranging from relatively mild to moderately severe. This is in contrast with the severe prenatal onset seen in ruminant beta-mannosidosis.

Argininosuccinate lyase (ASL) deficiency: mutation analysis in 27 patients and a completed structure of the human ASL gene.

Argininosuccinic aciduria is an urea cycle disorder caused by argininosuccinate lyase (ASL) deficiency and is inherited as an autosomal-recessive trait. To date, mutation analysis has been limited because of incomplete sequence information about the human ASL gene. As a consequence, only 12 different mutations in 12 patients have been reported, so far.

The gene for juvenile hyaline fibromatosis maps to chromosome 4q21.

Juvenile hyaline fibromatosis (JHF) is an autosomal recessive condition characterized by multiple subcutaneous nodular tumors, gingival fibromatosis, flexion contractures of the joints, and an accumulation of hyaline in the dermis. We performed a genomewide linkage search in two families with JHF from the same region of the Indian state of Gujarat and identified a region of homozygosity on chromosome 4q21. Dense microsatellite analyses within this interval in five families with JHF who were from diverse origins demonstrate that all are compatible with linkage to chromosome 4q21 (multipoint LOD score 5.

Molecular analysis of mutations in DNA polymerase eta in xeroderma pigmentosum-variant patients.

Xeroderma pigmentosum variant (XP-V) cells are deficient in their ability to synthesize intact daughter DNA strands after UV irradiation. This deficiency results from mutations in the gene encoding DNA polymerase eta, which is required for effecting translesion synthesis (TLS) past UV photoproducts. We have developed a simple cellular procedure to identify XP-V cell strains, and have subsequently analyzed the mutations in 21 patients with XP-V.