Cytogenomic aberrations in isolated multicystic dysplastic kidney in children.

Background: Multicystic dysplastic kidney (MCDK) is a common form of congenital kidney anomaly. The cause of MCDK is unknown. We investigated whether MCDK in children is linked to cytogenomic aberrations.

Duplication at Xq28 involving IKBKG is associated with progressive macrocephaly, recurrent infections, ectodermal dysplasia, benign tumors, and neuropathy.

Duplications on Xq28 are common, although quite variable in size, but usually include the MECP2 gene. Here, we present a patient with a unique, small, 167-kb duplication at Xq28, not including MECP2. The most important gene in the duplicated region was IKBKG, mutations in which can cause a variety of distinct syndromes.

Genotype-phenotype analysis of 4q deletion syndrome: proposal of a critical region.

Chromosome 4q deletion syndrome (4q- syndrome) is a rare condition, with an estimated incidence of 1 in 100,000. Although variable, the clinical spectrum commonly includes craniofacial, developmental, digital, skeletal, and cardiac involvement. Data on the genotype-phenotype correlation within the 4q arm are limited.

Genome-wide oligonucleotide array comparative genomic hybridization for etiological diagnosis of mental retardation: a multicenter experience of 1499 clinical cases.

To assess the clinical utility of genome-wide oligonucleotide arrays in diagnosis of mental retardation and to address issues relating to interpretation of copy number changes (CNCs), we collected results on a total of 1499 proband patients from five academic diagnostic laboratories where the same 44K array platform has been used. Three of the five laboratories achieved a diagnostic yield of 14% and the other two had a yield of 11 and 7%, respectively. Approximately 80% of the abnormal cases had a single segment deletion or duplication, whereas the remaining 20% had a compound genomic imbalance involving two or more DNA segments.

Similarity of DMD gene deletion and duplication in the Chinese patients compared to global populations.

Background: DNA deletion and duplication were determined as the major mutation underlying Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD).

Method: Applying multiplex ligation-dependent probe amplification (MLPA), we have analyzed 179 unrelated DMD/BMD subjects from northern China.

Results: Seventy-three percent of the subjects were found having a deletion (66.

Molecular analysis of mitochondrial DNA point mutations by polymerase chain reaction.

Mitochondrial respiratory chain disorders are clinically and genetically heterogeneous. There are several mitochondrial DNA (mtDNA) point mutations responsible for common mitochondrial diseases such as mitochondrial encephalopathy, lactic acidosis, stroke-like events, myoclonic epilepsy and ragged red fibers, neuropathy, ataxia, retinitis pigmentosa, and Leber's hereditary optic neuropathy. As a result of the clinical overlap, it is usually necessary to analyze more than one mutation for a patient suspected of a mitochondrial disorder.

Exercise intolerance associated with a novel 8300T > C mutation in mitochondrial transfer RNAlys.

Mutations in the mitochondrial genome contribute to the pathophysiology of many neuromuscular diseases. Recently there has been an increased appreciation of the role of mitochondrial DNA (mtDNA) mutations in the etiology of exercise intolerance. Using TTGE (temporal temperature-gradient gel electrophoresis) and sequence analyses of the entire mitochondrial genome, we identified a novel heteroplasmic mutation (8300T > C) in the tRNAlys gene (MTTK) from a patient with unexplained exercise intolerance.

A novel RSK2 (RPS6KA3) gene mutation associated with abnormal brain MRI findings in a family with Coffin-Lowry syndrome.

Coffin-Lowry syndrome (CLS) is an X-linked mental retardation syndrome caused by defects in the RSK2 gene. We have identified a CLS family with four patients in two generations. The patients in this family, a mother and her three children (a male and two females), all have severe mental retardation with the typical CLS phenotype.

Constitutional mosaic trisomy 21 and azoospermia: a case report.

Constitutional full trisomy 21 is a common disorder in which abnormal spermatogenesis has been previously described. However, constitutional mosaic trisomy 21 in an otherwise normal but infertile male has not been explored. We report a case with low level mosaic trisomy 21 in a non-syndrome but azoospermic patient.

Development of a molecular screening test for hereditary hearing loss and genetic susceptibility to aminoglycoside toxicity for Chinese population.

Objective: To develop a molecular screening test for genetic defects on hearing loss related genes has significant impacts on early identification of hereditary hearing loss and genetic susceptibility to aminoglycoside ototoxicity. Early identification of pre-lingual hearing loss is very important for patient' s language development, academic achievement, and social skill. Two common mutations, the 235delC in GJB2 gene and the mutation A1555G in mitochondrial DNA, are included in the newly developed screening panel for Chinese population.

Detection of mitochondrial DNA mutations using temporal temperature gradient gel electrophoresis.

Mitochondrial disorders are a group of clinically and genetically heterogeneous diseases. Common recurrent mitochondrial DNA (mtDNA) point mutations account for the molecular defects of a small proportion of patients. In order to identify mtDNA mutations, comprehensive mutational analysis of the entire mitochondrial genome is necessary.

Variable clinical manifestation of homoplasmic G14459A mitochondrial DNA mutation.

Leber hereditary optic neuropathy (LHON)/pediatric onset dystonia is associated with a G to A transition at nucleotide position (np) 14459, within the mitochondrial DNA (mtDNA)-encoded ND6 gene. This mutation has been reported in families presenting with LHON alone, LHON plus dystonia, or pediatric dystonia with typical age of onset less than 5 years. The mutation changes a moderately conserved alanine to a valine at amino acid residue 72, which is within the most evolutionarily conserved region of the ND6 protein.