OBJECTIVE: To screen for mutations of fragile X mental retardation 1 (FMR1) gene during early and middle pregnancy and provide prenatal diagnosis for those carrying high-risk CGG trinucleotide expansions. METHODS: Peripheral blood samples of 2316 pregnant women at 12 to 21(+6) gestational weeks were collected for the extraction of genomic DNA. CGG repeats of the FMR1 gene were detected by fluorescence PCR and capillary electrophoresis. Genetic counseling and prenatal diagnosis were provided for 3 women carrying the premutations. RESULTS: The carrier rate of CGG repeats of the FMR1 gene was 1 in 178 for the intermediate type and 1 in 772 for the premutation types. The highest frequency allele of CGG was 29 repeats, which accounted for 49.29%, followed by 30 repeats (28.56%) and 36 repeats (8.83%). In case 1, the fetus had a karyotype of 45,X, in addition with premutation type of CGG expansion of the FMR1 gene. Following genetic counseling, the couple chose to terminate the pregnancy through induced labor. The numbers of CGG repeats were respectively 70/- and 29/30 for the husband and wife. In case 2, amniocentesis was performed at 20 weeks of gestation. The number of CGG repeats of the FMR1 gene was 29/-. No abnormality was found in the fetal karyotype and chromosomal copy number variations. The couple chose to continue with the pregnancy. Case 3 refused prenatal diagnosis after genetic counseling and gave birth to a girl at full term, who had a birth weight of 2440 g and no obvious abnormality found during follow-up. CONCLUSION Pregnant women should be screened for FMR1 gene mutations during early and middle pregnancy, and those with high-risk CGG expansions should undergo prenatal diagnosis, genetic counseling and family study.
DNA Copy Number Variations ; Female ; Fragile X Mental Retardation Protein/genetics* ; Fragile X Syndrome/genetics* ; Genetic Counseling ; Humans ; Mutation ; Pregnancy ; Trinucleotide Repeat Expansion ; Trinucleotide Repeats

OBJECTIVETo analyze mutations of SLC26A4 gene and explore their origins for a patient with enlarge vestibuar aqueduct syndrome.

METHODSClinical data and peripheral venous blood samples were collected from the patient and her parents. Genome DNA was extracted from the peripheral blood. All of the 21 exons of the SLC26A4 gene were amplified with PCR and subjected to directly sequencing.

RESULTSThe patient was found to have carried two mutant alleles of the SLC26A4 gene, namely c.1522A to G and c.1229C to T, which were inherited from her father and mother, respectively.

CONCLUSIONSLC26A4 c.1522A to G is likely to be a pathogenic mutation. Above results may facilitate genetic counseling and prenatal diagnosis for this family.

Adult ; Amino Acid Sequence ; Child ; Exons ; Female ; Hearing Loss, Sensorineural ; genetics ; Humans ; Male ; Membrane Transport Proteins ; genetics ; Molecular Sequence Data ; Pedigree ; Vestibular Aqueduct ; abnormalities

Botulinum toxin(BoNT)is currently the first-line method for treating focal dystonia,which causes muscle paralysis by chemical denervation.Recent neuroimaging studies have found that BoNT treatment could alter neuroplasticity in the brain of patients with focal dystonia.However,the specific central nervous system mechanisms have not been fully elucidated.To this end,here we review the neuroimaging studies on BoNT treatment for dystonia from three aspects:functional magnetic resonance imaging,structural magnetic resonance imaging,and positron emission tomography imaging.It suggests that BoNT may improve the symptoms of dystonia patients by affecting functional connectivity,microstructure,and metabolic levels of the cortex,basal ganglia,thalamus,and cerebellum,etc.Therefore,this review will provide a theoretical reference for further exploring the mechanism and developing potential therapeutic targets of dystonia.