Cockayne syndrome is a rare autosomal recessive disease. This paper reports a case of Cockayne syndrome confirmed by gene analysis. The baby (male, 7 years old) was referred to Peking University Third Hospital with recurrent desquamation, pigmentation and growth and development failure for 6 years, and recurrent dental caries and tooth loss for 2 years. Physical examination showed very low body weight, body length and head circumference, yellow hair, a lot of fawn spots on the face, skin dry and less elastic, and subcutaneous lipopenia. He had an unusual appearance with sunken eyes, sharp nose, sharp mandible, big auricle and dental caries and tooth loss. Crura spasticity and ataxia with excessive tendon reflexion, and ankle movement limitation while bending back were observed. He had slured speech. The level of serum insulin like growth factor I was low, and the results of blood and urinary amino acid analysis suggested malnutrition. The results of blood growth hormone, thyroxin, parathyroxin, liver function, renal function, lipoprotein profile and blood glucose and electrolytes were all within normal limit. An electronic hearing examination showed moderate neural hearing loss. The sonogram of eyes revealed small eye axis and vitreous body opacity of right side. MRI of brain revealed bilateral calcification of basal ganglia and generalized cerebral and cerebellar atrophy, and brainstem and callus were also atrophic. Genetic analysis confirmed with CSA gene mutation. So the boy was definitely diagnosed with Cockayne syndrome. He was discharged because of no effective treatment.
Child ; Cockayne Syndrome ; diagnosis ; genetics ; therapy ; Diagnosis, Differential ; Humans ; Male

Humans ; Cockayne Syndrome/genetics* ; Genetic Association Studies ; Phenotype

Ultraviolet light(UV)-sensitive disorders refer to a group of diseases due to damages to the nucleotide excision repair mechanism which cannot effectively repair DNA damage caused by ultraviolet radiation. The inheritance pattern of such diseases, mainly including xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy, is autosomal recessive and known to involve 13 genes. As proteins encoded by such genes are involved in DNA repair and transcription pathways. There is overlap between the symptoms of such diseases, and their genotype - phenotype correlations are quite complex. To facilitate genetic and prenatal diagnosis for such diseases, a summary of the research progress is provided, which mainly focused on mutation research and genotype - phenotype correlation studies. We also propose a strategy for their genetic diagnosis based on recent findings of our group.
Biomedical Research ; methods ; trends ; Cockayne Syndrome ; genetics ; DNA Damage ; DNA Repair ; genetics ; Genetic Predisposition to Disease ; genetics ; Humans ; Skin ; metabolism ; pathology ; radiation effects ; Trichothiodystrophy Syndromes ; genetics ; Ultraviolet Rays ; Xeroderma Pigmentosum ; genetics

OBJECTIVETo identify potential mutations among three sisters from a Chinese family suspected with Cockayne syndrome for growth and psychomotor retardation, and to offer genetic counseling and prenatal diagnosis for the family.

METHODSG-banded karyotyping, microarray comparative genomic hybridization (CM-CGH), whole genome exon high-throughput sequencing and Sanger sequencing were employed to identify potential genetic variations for the three patients and their parents.

RESULTSWhole exome sequencing has identified two novel missense mutations, i.e., c.1595A>G (p.Asp532Gly) and c.1607T>G (p.Leu536Trp), in exon 7 of excision repair cross-complementing rodent repair deficiency, complementation group 6 (ERCC6) gene. Sanger sequencing confirmed that all of the three sisters have inherited one of the mutations (c.1607T>G) from their father and another (c.1595A>G) from their mother.

CONCLUSIONThree sisters have all been identified as double heterozygote for mutations c.1607T>G and c.1595A>G and were diagnosed with Cockayne syndrome.

Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child, Preschool ; Cockayne Syndrome ; diagnosis ; genetics ; DNA Helicases ; genetics ; DNA Repair Enzymes ; genetics ; Exons ; Female ; Heterozygote ; Humans ; Infant ; Male ; Molecular Sequence Data ; Pedigree ; Point Mutation ; Poly-ADP-Ribose Binding Proteins

OBJECTIVECockayne syndrome is a rare disease and difficult to be recognized. This study aimed to expand the knowledge of the clinical and molecular characteristics of the children with Cockayne syndrome (CS).

METHODClinical data of two siblings with classic CS of Guangzhou Women and Children's Medical Center from July 2013 to November 2014 were obtained and analyzed. The whole DNA of peripheral blood was collected from two CS siblings and their parents. Amplification of all exons and adjacent introns for ERCC6 gene was conducted using PCR, and measurement of reaction product was performed to find mutation sites by two-way sequencing.

RESULTTwo affected siblings were males, and came from unconsanguineous parents, 7 years and 5 months old and 4 years and 8 months old, respectively. They were in treatment because of developmental and mental retardation for years. When they were younger than one year of age, their heights and weight were within normal limits. However, poor growth of height and weight and psychomotor retardation appeared after one and a half years of age, as well as skin and eye sensitivity to sunshine, hearing impairment, optic nerve atrophy, microcephaly, and deep-set eyes. The proband's height was 90.8 cm, and weight 9.1 kg, head circumference 41 cm, and chest circumference 44 cm when he was taken to hospital. The elder brother of the proband had a height of 92 cm, weight 11.2 kg, head circumference 41 cm, and chest circumference 44 cm when he was taken to hospital. When the proband was four and a half years old, ventricular enlargement, hypomyelination, and brain atrophy were detected for his elder brother at 7 years of age by cranial MRI. MRS imaging indicated that damages occurred at the left and right sides of dorsal thalamus, lobus insularis, along with the left half circle of central neurons. Symmetrical calcification on bilateral basal ganglia was found on the brain CT scan. Pathogenic compound heterozygous c. 1357C > T (p.Arg453Ter) and c. 1607T > G (p.Leu536Trp) mutations of ERCC6 gene were identified in the two siblings which were separately inherited from their unaffected parents.

CONCLUSIONCS children are usually normal at birth, however, they have severe clinical characteristics such as poor growth, psychomotor retardation, cerebral injury, microcephalus, deep-set eyes, and skin sensitivity to sunshine. ERCC6 gene mutation usually occurs, and it is easy to misdiagnose CS as cerebral palsy, primary microcephaly, and so on.

Asian Continental Ancestry Group ; Child ; Child, Preschool ; Cockayne Syndrome ; genetics ; DNA Helicases ; genetics ; DNA Mutational Analysis ; DNA Repair Enzymes ; genetics ; Exons ; Heterozygote ; Humans ; Magnetic Resonance Imaging ; Male ; Mutation ; Poly-ADP-Ribose Binding Proteins ; Polymerase Chain Reaction ; Siblings

BACKGROUNDCockayne syndrome (CS) is a rare human genetic disorder characterized by increased UV sensitivity, developmental abnormalities and premature aging. Cells isolated from individuals with CS have a defect in transcription-coupled DNA repair. Despite the repair defect, there is no any increased risk of spontaneous or UV-induced cancer for CS individuals. The strategy of RNA interfering was used here to explore the potential radiosensitizing and anticancer activity of targeting CS group B (CSB) gene.

METHODSThe vectors encoding CSB-specific siRNAs were constructed by inserting duplex siRNA encoding oligonucleotides into the plasmid P(silencer TM 3.1). The cell lines expressing the CSB-siRNA were generated from HeLa cells transfected with the above vectors. Colony-forming ability was used to assay cell survival. Cell cycle was analyzed by FACScan flow cytometry. The apoptosis was measured by detecting the accumulation of sub-G(1) population as well as by fluorescence staining assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to semi-quantify mRNA expression. Protein level was detected by Western blotting analysis.

RESULTSTwo constructs encoding CSB-specific siRNA were generated, both of them resulted in remarkable suppression on CSB expression in HeLa cells, and led to an increased sensitivity to (gamma-ray and UV light. siRNA-mediated silencing of CSB decreased cell proliferation rate, increased spontaneous apoptosis as well as the occurrence of UV- or cisplatin-induced apoptosis by 2 to 3.5 fold. A significant S phase blockage and a remarkable reduction of G(1) population were induced in control HeLa cells at 18 hours after being exposed to 10 J/m(2) of UV light. The S phase blockage was also observed in UV-irradiated CSB-siRNA transfected HeLa cells, but the extent of increased S phase population was lower than that in the UV-irradiated control cells. No or a relative weak reduction on G(1) phase population was observed in UV-irradiated CSB-siRNA transfected HeLa cells. In addition, siRNA-mediated silencing of CSB promoted the elimination of G(2)/M phase cells after UV light radiation.

CONCLUSIONSsiRNA-mediated silencing of CSB causes cells to proliferate more slowly, sensitize cells to genotoxicants, and modify UV radiation-induced cell cycle changes. siRNA-mediated inactivation of CSB could be an attractive strategy for ameliorating cancer therapy, which can be fulfilled via the combination of gene therapy and sensitization of radiotherapy or chemotherapy.

Apoptosis ; radiation effects ; Cell Cycle ; radiation effects ; Cell Proliferation ; radiation effects ; Cisplatin ; pharmacology ; Cockayne Syndrome ; genetics ; Gene Silencing ; Genetic Therapy ; HeLa Cells ; radiation effects ; Humans ; RNA, Small Interfering ; genetics ; Radiation Tolerance ; Ultraviolet Rays