OBJECTIVETo establish a simple, rapid genetic diagnostic system for haemophilia B.

METHODSThe polymorphisms of eight STR loci in 87 normal persons and 8 haemophilia B families were assayed by PCR and genescan, and the linkage relations were analysed.

RESULTSSix of the eight STR loci can provide genetic information for haemophilia B, and the heterozygosity is 0.50 approximately 0.83, PIC 0.39 approximately 0.80, and DP 0.66 approximately 0.94.

CONCLUSIONCombination of multiple STR loci analysis could be effective method for genetic diagnosis of haemophilia B.

Female ; Genetic Carrier Screening ; methods ; Genetic Linkage ; Genetic Predisposition to Disease ; Hemophilia B ; diagnosis ; genetics ; Humans ; Male ; Microsatellite Repeats ; genetics ; Pedigree ; Polymorphism, Genetic

Child, Preschool ; Flow Cytometry ; methods ; Genetic Carrier Screening ; Granulomatous Disease, Chronic ; diagnosis ; genetics ; Humans ; Infant ; Male

This study was aimed to investigate the prevalence and genotype distribution of heterozygotes in beta-thalassemia combining deletional alpha-thalassemia by using molecular detection and haematological methods. Three common deletions of alpha-thalassemia were detected by using gap-PCR. The mutations of beta-thalassemia were identified by using PCR with reverse dot blot hybridization. The routine analysis of blood cells was carried out. The results indicated that 15 cases from the 81 beta-thalassemia traits were found to be the compound heterozygosity for beta-thalassemia and alpha-thalassemia with 9 different types of gene defects with 18.52% detection rate. There were 6 cases (7.41%) of beta-thalassemia heterozygote combining alpha-thalassemia-1 gene (--(SEA)/alphaalpha), 8 cases (9.88%) combining with alpha-thalassemia-2 gene including 6 (7.41%) right ward deletion (-alpha(3.7)/alphaalpha) and 2 (2.47%) left ward deletion (-alpha(4.2)/alphaalpha), and 1 case (1.23%) combining deletional HbH gene (--(SEA)/-alpha(3.7)). No significant differences were found between beta-thalassemia heterozygotes combining deletional alpha-thalassemia and pure beta-thalassemia in all RBC parameters. It is concluded that the incidence of beta-thalassemia heterozygotes combining with deletional alpha-thalassemia is frequent in Wuzhou city. The hematological analysis can not give specificity for diagnosing these dual heterozygotes. Gap-PCR as a routine method for thalassemia screening has the advantages in reducing the possibility of failing to detect the combining heterozygosity for beta-thalassemia and alpha-thalassemia. It is more useful for genetic counselling and prenatal diagnosis of this disease.
Adolescent ; Adult ; Female ; Gene Deletion ; Genetic Carrier Screening ; methods ; Genotype ; Heterozygote ; Humans ; Male ; alpha-Thalassemia ; genetics ; beta-Thalassemia ; genetics

PURPOSE: Short stature affects approximately 2%–3% of children, representing one of the most frequent disorders for which clinical attention is sought during childhood. Despite assumed genetic heterogeneity, mutations or deletions in the short stature homeobox-containing gene (SHOX) are frequently detected in subjects with short stature. Idiopathic short stature (ISS) refers to patients with short stature for various unknown reasons. The goal of this study was to screen all the exons of SHOX to identify related mutations. METHODS: We screened all the exons of SHOX for mutations analysis in 105 ISS children patients (57 girls and 48 boys) living in Taif governorate, KSA using a direct DNA sequencing method. Height, arm span, and sitting height were recorded, and subischial leg length was calculated. RESULTS: A total of 30 of 105 ISS patients (28%) contained six polymorphic variants in exons 1, 2, 4, and 6. One mutation was found in the DNA domain binding region of exon 4. Three of these polymorphic variants were novel, while the others were reported previously. There were no significant differences in anthropometric measures in ISS patients with and without identifiable polymorphic variants in SHOX. CONCLUSION: In Saudi Arabia ISS patients, rather than SHOX, it is possible that new genes are involved in longitudinal growth. Additional molecular analysis is required to diagnose and understand the etiology of this disease.
Arm ; Child* ; DNA ; Exons ; Female ; Genetic Heterogeneity ; Humans ; Leg ; Mass Screening* ; Methods ; Saudi Arabia ; Sequence Analysis, DNA

Fetal nucleated erythrocytes circulating in maternal blood are a potential source of fetal DNA for noninvasive prenatal genetic diagnosis. However, the estimated ratio of fetal to maternal cells is extremely small. In order to enrich these cells, we performed direct culture using a two-phase liquid system. Mononuclear cells were obtained from maternal blood samples at 8-10(+3) weeks of gestation and cultured in the first phase. After 4-5 days, the nonadherent cells were harvested and recultured with erythropoietin in the second phase for another 3-5 days. We examined cellular morphology, and counted the number of benzidine- positive cells and the percentage of glycophorin A/CD71 positive erythroid cells. We also did Kleihauer-Betke stain for Hb F, polymerase chain reaction (PCR) for SRY/DYZ1, chromosome analysis, and fluorescence in situ hybridization (FISH). The number of total erythroid cells reached about 0.1x10(6)-1.0x10(6)/mL with a purity of 84.0-97.3%. Hb F stain showed total erythroid cells of approximately 0.4x10(4)-9.8x10(4)/mL. Male DNA was detected in one case by PCR. In this case, the XY karyotype was confirmed by FISH and amniocentesis. This approach provides enriched source of fetal cells for further prenatal genetic analysis without complicated separation or sorting procedures.
Cell Culture/methods ; Cell Separation/*methods ; Chromosome Abnormalities/diagnosis ; *Erythroblasts ; Female ; Genetic Screening ; Human ; *In Situ Hybridization, Fluorescence ; Karyotyping ; *Maternal-Fetal Exchange ; Pregnancy ; sPrenatal Diagnosis/*methods

OBJECTIVETo set up thalassemia population intervention model in order to decrease the birth of thalassemia major, relying on population and family planning service system.

METHODSPregnant women and their husbands were educated about thalassemia, and participated in screening and prenatal diagnosis if the couple were carriers of thalassemia in the areas of Huangpu, Panyu, Zengcheng and Tianhe districts of Guangzhou.

RESULTSThe network of thalassemia intervention mainly dependent on family planning service system was set up in these regions. A total of 10 695 families participated in thalassemia screening and 16 thalassemia major fetuses were diagnosed in the last two years. No one was thalassemia major in the 8360 newborn.

CONCLUSIONThalassemia population intervention model was set up relying on family planning service system and it significantly decreased the birth of thalassemia major.

Family Planning Services ; methods ; Female ; Genetic Counseling ; Heterozygote ; Humans ; Infant, Newborn ; Male ; Mass Screening ; methods ; Pregnancy ; Prenatal Diagnosis ; methods ; Spouses ; Thalassemia ; diagnosis ; genetics ; prevention & control

The majority of cases of Charcot-Marie-Tooth type 1A (CMT1A) and of hereditary neuropathy with a liability to pressure palsies (HNPP) are the result of heterozygosity for the duplication or deletion of peripheral myelin protein 22 gene (PMP22) on 17p11.2. Southern blots, pulsed-field gel electrophoresis (PFGE), fluorescence in situ hybridization (FISH) and polymorphic marker analysis are currently used diagnostic methods. But they are time-consuming, labor-intensive and have some significant limitations. We describe a rapid real- time quantitative PCR method for determining gene copy number for the identification of DNA duplication or deletion occurring in CMT1A or HNPP and compare the results obtained with REP-PCR. Six patients with CMT1A and 14 patients with HNPP [confirmed by Repeat (REP) -PCR], and 16 patients with suspicious CMT1A and 13 patients with suspicious HNPP [negative REP-PCR], and 15 normal controls were studied. We performed REP-PCR, which amplified a 3.6 Kb region (including a 1.7Kb recombination hotspot), using specific CMT1A-REP and real-time quantitative PCR on the LightCycler system. Using a comparative threshold cycle (Ct) method and beta-globin as a reference gene, the gene copy number of the PMP22 gene was quantified. The PMP22 duplication ratio ranged from 1.35 to 1.74, and the PMP22 deletion ratio from 0.41 to 0.53. The PMP22 ratio in normal controls ranged from 0.81 to 1.12. All 6 patients with CMT1A and 14 patients with HNPP confirmed by REP-PCR were positive by real-time quantitative PCR. Among the 16 suspicious CMT1A and 13 suspicious HNPP with negative REP-PCR, 2 and 4 samples, respectively, were positive by real-time quantitative PCR. Real-time quantitative PCR is a more sensitive and more accurate method than REP-PCR for the detection of PMP22 duplications or deletions, and it is also faster and easier than currently available methods. Therefore, we believe that the real-time quantitative method is useful for diagnosing CMT1A and HNPP.
Charcot-Marie-Tooth Disease/*diagnosis/*genetics ; Comparative Study ; Gene Dosage ; Genetic Screening/methods ; Hereditary Motor and Sensory Neuropathies/*diagnosis/*genetics ; Humans ; Polymerase Chain Reaction/*methods

OBJECTIVETo assess the value of droplet digital PCR (ddPCR) for non-invasive prenatal diagnosis of single gene disease in two families.

METHODSPaternal mutation in cell-free DNA derived from the maternal blood and amniotic fluid DNA was detected by ddPCR. Suspected mutation in the amniotic fluid DNA was verified with Sanger sequencing.

RESULTSThe result of ddPCR and Sanger sequencing indicated that the fetuses have carried pathogenic mutations from the paternal side in both families.

CONCLUSIONDroplet digital PCR can accurately detect paternal mutation carried by the fetus, and it is sensitive and reliable for analyzing trace samples. This method may be applied for the diagnosis of single gene diseases caused by paternal mutation using peripheral blood sample derived from the mother.

Fathers ; Female ; Genetic Diseases, Inborn ; diagnosis ; Humans ; Male ; Maternal Serum Screening Tests ; Mutation ; Polymerase Chain Reaction ; methods ; Prenatal Diagnosis ; methods ; Sequence Analysis, DNA

OBJECTIVE: To analyze the clinical significance of combined newborn hearing and deafness gene screening in Yuncheng area of Shanxi Province. METHODS: Results of audiological examinations, including transient evoked otoacoustic emission and automatic discriminative auditory brainstem evoked potentials, for 6 723 newborns born in Yuncheng area from January 1, 2021 to December 31, 2021, were retrospectively analyzed. Those who failed one of the tests were considered to have failed the examination. A deafness-related gene testing kit was used to detect 15 hot spot variants of common deafness-associated genes in China including GJB2, SLC26A4, GJB3, and mtDNA12S rRNA. Neonates who had passed the audiological examinations and those who had not were compared using a chi-square test. RESULTS: Among the 6 723 neonates, 363 (5.40%) were found to carry variants. These have included 166 cases (2.47%) with GJB2 gene variants, 136 cases (2.03%) with SLC26A4 gene variants, 26 cases (0.39%) with mitochondrial 12S rRNA gene variants, and 33 cases (0.49%) with GJB3 gene variants. Among the 6 723 neonates, 267 had failed initial hearing screening, among which 244 had accepted a re-examination, for which 14 cases (5.73%) had failed again. This has yielded an approximate prevalence of hearing disorder of 0.21% (14/6 723). Among 230 newborns who had passed the re-examination, 10 (4.34%) were found to have carried a variant. By contrast, 4 out of the 14 neonates (28.57%) who had failed the re-examination had carried a variant, and there was a significant difference between the two groups (P < 0.05). CONCLUSION Genetic screening can provide an effective supplement to newborn hearing screening, and the combined screening can provide a best model for the prevention of hearing loss, which can enable early detection of deafness risks, targeted prevention measures, and genetic counseling to provide accurate prognosis for the newborns.
Infant, Newborn ; Humans ; Connexins/genetics* ; Retrospective Studies ; Deafness/genetics* ; Connexin 26/genetics* ; Neonatal Screening/methods* ; Mutation ; Genetic Testing/methods* ; China/epidemiology* ; Hearing ; DNA Mutational Analysis

OBJECTIVEDystrophin gene deletion junction is the unique DNA sequence resulted from illegitimate recombination after the gene deletion. A novel accurate approach is presented here for the detection of deletional pseudohypertrophic muscular dystrophy carriers with the deletion junctions.

METHODSA Becker muscular dystrophy (BMD) family from Zhaoqing, Guangdong, China was used. Two males in the family were diagnosed as BMD patients, 3 phenotypically normal females and 1 chorionic villi sample of an artificial abortion were waiting for diagnosis. The index patient was identified as exons 3-5 deletion of the dystrophin gene. Then a PCR-based genome-walking method was used to locate the breakpoints in corresponding introns. Finally, deletion junctions of the 6 family members were amplified by PCR with primers adjacent to breakpoints and sequenced.

RESULTSThe deletion junctions of all patients and carriers of the BMD family were cloned and sequenced. The 3 females and 1 chorionic tissue were diagnosed as female carriers.

CONCLUSIONIn this study researchers have successfully carried out accurate gene diagnosis of deletional pseudohypertrophic carriers by cloning and sequencing the deletion junctions, and explored the prospect of using deletion junctions in prenatal diagnosis of BMD.

Base Sequence ; Cloning, Molecular ; DNA Mutational Analysis ; Female ; Gene Deletion ; Genetic Carrier Screening ; methods ; Humans ; Male ; Molecular Sequence Data ; Muscular Dystrophy, Duchenne ; diagnosis ; genetics ; Pedigree ; Polymerase Chain Reaction ; methods ; Pregnancy ; Prenatal Diagnosis ; Recombination, Genetic