Diagnosis of the accurate genotype of HKαα carriers in patients with thalassemia using multiplex ligation-dependent probe amplification combined with nested polymerase chain reaction / 中华医学杂志(英文版)

BACKGROUND@#Patients carrying the HongKongαα (HKαα) allele and -α/ααα could be misdiagnosed as -α/αα by the current conventional thalassemia detection methods, leading to inaccurate genetic counseling and an incorrect prenatal diagnosis. This study was aimed to accurately analyze the genotypes of HKαα carriers and -α/ααα.@*METHODS@#Samples were collected in our hospital from July 2017 to October 2019. Twenty-four common types of Chinese thalassemia were screened by gap-polymerase chain reaction (Gap-PCR) and reverse dot blot (RDB). Anti-4.2 multiplex-PCR was used to confirm carriers of the ααα duplication with -α deletion. Two-round nested PCR and multiplex ligation-dependent probe amplification (MLPA) were applied to accurately identify and confirm their genotypes. For data analysis, we used descriptive statistics and Fisher's exact tests.@*RESULTS@#Two thousand five hundred and forty-four cases were identified as thalassemia in 5488 peripheral blood samples. The results showed that α, β, and αβ compound thalassemia were identified in 1190 (46.78%), 1286 (50.55%), and 68 (2.67%) cases, respectively. A total of 227 samples from thalassemia patients were identified as -α/αα by Gap-PCR, and the genotypes of two samples were uncertain. There was a difference between Gap-PCR and combined groups (Gap-PCR combined with nested PCR and MLPA) in detecting HKαα (P < 0.05). Among the 229 patients, 20 patients were identified as HKαα carriers and one was identified as -α/ααα by two-round nested PCR and MLPA, including 15 patients with HKαα/αα, three with HKαα/αα and β-thalassemia coinheritance, one with HKαα/--, one with HKαα/-α and β-thalassemia coinheritance, and one with -α/ααα and β-thalassemia coinheritance.@*CONCLUSIONS@#ααα and HKαα genotypes of patients carrying -α need to be detected to reduce the misdiagnosis rate of patients carrying HKαα and -α3.7/ααα alleles. More accurate genetic counseling can be provided in the clinic using nested PCR combined with MLPA.

Clinical characteristics and gene analysis of vitreous amyloidosis in a Chinese kindreds / 中华实验眼科杂志

Background Familial vitreous amyloidosis is a rare ocular regional amyloidosis,and it is a kind of autosomal dominant inheritance disease.Familial vitreous amyloidosis demonstrates a variable penetrance due to the mutation in the plasma thyroid hormone-binding protein transtheretin (TTR) gene.Many studies have reported over 100 types of TTR genetic mutation in Switzerland,Portugal and Japan,but rare in China.Objective This survey aimed to investigate the clinical and genetic mutation characteristics in familial vitreous amyloidosis.Methods Physical and eye examinations were performed on 52 family members of this vitreous amyloidosis family.Peripheral blood samples from 52 members were collected for TTR gene test by DNA extract,PCR amplification,clone,bolting and sequencing.Pars plana vitrectomy was firstly performed prior to the pathological examination of vitreous sample on 13 eyes of 8 members.Informed consent was obtained from each individual before any medical procedure.Results Seventeen members suffered from vitreous amyloidosis in this family without nervous system,heart,kidney and liver disease.Vitreous opacity was found in 34 eyes of the 17 members,and retinal vasculopathy was seen in 28 eyes of 15 members.In addition,cataract appeared in 16 eyes of 10 members.None of the members had glaucoma or ocular motility disorders.Congo red test of vitreous specimens showed a positive result in 13 eyes of 8 patients who received vitrectomy.Point mutation was verified on the 83th amine acid location of exon 3 (Gly83Arg) in TTR gene by gene sequencing.Conclusions Clinical characteristics of familial vitreous amyloidosis induced by TTR gene Arg-83 mutation is rate retinal vasculopathy without glaucoma,other ocular regional disease and systemic diseases.

Association analysis of genetic polymorphisms of TCF7L2, CDKAL1, SLC30A8, HHEX genes and microvascular complications of type 2 diabetes mellitus / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the associations of single nucleotide polymorphisms (SNPs) of TCF7L2, CDKAL1, SLC30A8, HHEX with diabetic retinopathy (DR) and nephropathy (DN) in type 2 diabetes mellitus.</p><p><b>METHODS</b>A total of 479 subjects with DR,248 with DN and 650 without DR or DN were recruited to assess the associations between SNPs of TCF7L2 (rs7903146, rs6585205, rs11196218), CDKAL1 (rs10946398,rs4712527), SLC30A8 (rs13266634, rs3802177, rs11558471) and HHEX (rs1111875, rs7923837) and the development of DR and DN.</p><p><b>RESULTS</b>There were significant differences in genotypic and allele frequencies of rs11558471 (SLC30A8) between DR and control groups (P< 0.05), the odds ratio (OR) values of A and AA were 1.27 and 1.68. The distributions of genotype and allele frequency for rs11196218 (TCF7L2) were significantly different between DN and control group (P=0.0051,OR=1.37). However, the P value after Bonferroni correction showed no significant difference. No significant differences were found in the distributions of rs13266634 and rs3802177 (SLC30A8), rs10946398 (CDKAL1), rs6585205, rs7903146 and rs11196218 (TCF7L2) and rs7923837 (HHEX) between DR and control groups, and nor significant differences were found in distributions of rs6585205 (TCF7L2), rs4712527 (CDKAL1), rs13266634, rs3802177 and rs11558471 (SLC30A8), and 7923837 (HHEX) between DN and control groups, though for all comparison the OR values were greater than 1.</p><p><b>CONCLUSION</b>Polymorphisms of SLC30A8 and TCF7L2 genes may be associated with the development of DR and DN, respectively. Association between the polymorphisms of CKDAL1, TCF7L2 and HHEX genes and DR, and between the polymorphisms of SLC30A8, HHEX and CDKAL1 genes and DN, cannot be excluded.</p>

Prognostic power of abnormal cytogenetics for multiple myeloma: a multicenter study in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Chromosomal abnormalities have been shown to play an important prognostic role in multiple myeloma (MM). Interphase fluorescence in situ hybridization (i-FISH) has been much more effective to identify cytogenetic aberrations in MM than conventional cytogenetic technique (CC). To clearly determine the cytogenetic features of Chinese MM patients and identify their prognostic implications, we designed a multicenter study based on i-FISH including 672 patients from 52 hospitals in China.</p><p><b>METHODS</b>All 672 patients were systematically screened for the following genomic aberrations: del(13q), IgH rearrangement, del(p53) and 1q21 amplifications.</p><p><b>RESULTS</b>The analysis showed that the chromosomal changes were detected in 22.1% patients by CC and in 82.3% patients by i-FISH. The most common abnormalities by CC were chromosome 1 aberrations (48.4%), -13/13q- (37.6%), hyperdiploidy (36.6%), hypodiploidy (30.1%) and IgH rearrangements (23.7%). The most frequent abnormalities by FISH was del(13q), which was found in 60.4% patients, whereas IgH rearrangement, 1q21 amplification and p53 deletions were detected in 57.6%, 49.0% and 34.7% cases, respectively. By statistical analysis, -13/13q- by CC was associated with low level of platelet (P = 0.015), hyperdiploidy was associated with low level of serum albumin (P = 0.028), and IgH rearrangement by FISH was associated with high level of β2 microglobulin (P = 0.019). Moreover, 1q21 amplification and del(p53) by FISH conferred a high incidence of progressive disease (PD) after initial therapy. Metaphase detection of IgH rearrangements and chromosome 1 aberrations concurrently was associated with a short progression free survival (PFS) (P = 0.036). No significant prognostic implications of other cytogenetic abnormalities were found associated with overall survival and PFS.</p><p><b>CONCLUSIONS</b>Chinese MM patients had similar cytogenetic abnormalities compared with the previous reported studies. However, the prognostic significance of FISH aberrations were not clearly determined and further study is required.</p>

Association study between age-related macular degeneration and R1210C mutation of CFH gene in Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>A R1210C mutation of complement factor H (CFH) gene has been associated with age-related macular degeneration (AMD) in Caucasian population. This study was to verify above association in Han Chinese population.</p><p><b>METHODS</b>The mutation was detected by direct sequencing in 258 patients with wet AMD and 426 matched controls.</p><p><b>RESULTS</b>The R1210C mutation has not been identified in either sample.</p><p><b>CONCLUSION</b>The R1210C mutation in CFH gene is not associated with AMD in Han Chinese population.</p>

Association study on single nucleotide polymorphisms in HTRA1 gene and rheumatoid arthritis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the association between the single nucleotide polymorphisms (SNPs) in the high-temperature requirement A-1 (HTRA1) gene and rheumatoid arthritis (RA) in Chinese Han population.</p><p><b>METHODS</b>Five SNPs in the HTRA1 gene (rs2014307, rs2248799, rs2300433, rs714816 and rs2268356) were genotyped by ABI Snapshot method in Han Chinese cohort composed of 344 patients with RA and 288 healthy controls. The serum rheumatoid factor (RF) and C-reactive protein (CRP) of the patients were determined by endpoint nephelometry method.</p><p><b>RESULTS</b>Genotypes of all the five SNPs in the HTRA1 gene were not significantly different between the RA patients and controls (P> 0.05). Haplotypes generated by these five SNPs did not show significantly difference between the two groups either (P> 0.05). Serum RF levels in the RA patients had no significant difference among the genotypes for four SNPs (rs2014307, rs2248799, rs714816, and rs2268356) in the HTRA1 gene, while RF levels in the RA patients with genotypes AA+AG of the rs2300433 locus were significantly higher than that in genotype GG carriers (P< 0.05). Serum CRP levels in the RA patients had no significant difference among the genotypes for all the five SNPs.</p><p><b>CONCLUSION</b>Author's results suggested that although the five SNPs in the HTRA1 gene were not associated with RA in Chinese Han population, RF levels in the RA patients with genotypes AA and AG in the rs2300433 locus were significantly higher than the GG carriers. The HTRA1 role in RF regulation needs to be further investigated.</p>

Mutation analysis of the PAX6 gene in a family with congenital aniridia and cataract / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutation in the PAX6 gene in a family with congenital aniridia and cataract.</p><p><b>METHODS</b>Total genomic DNA was extracted from peripheral blood leukocytes of 12 family members including three living affected members and 96 unrelated healthy controls. The coding exons 4-13 of the PAX6 gene with intronic flanking sequences were amplified by polymerase chain reaction (PCR). By comparing sequences of the affected members with that of normal individuals, the disease-causing mutation was detected by direct DNA sequencing.</p><p><b>RESULTS</b>A PAX6 mutation was identified in the 3 patients, which did not exist in the unaffected members and unrelated healthy individuals. The nonsense mutation of C to T was detected at the nucleotide 1143, which converted the Arg codon (CGA) to a stop codon(TGA) (R261X) in exon 10.</p><p><b>CONCLUSION</b>The mutation (R261X) detected in the present study is considered to result in the occurrence of congenital aniridia and cataract in the Chinese family.</p>

Linkage analysis of a family with familial hypertriglyceridemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform linkage analysis and mutation screening in a Chinese family with familial hpertriglyceridemia (FHTG).</p><p><b>METHODS</b>Thirty-two family members including 12 hypertriglyceridemia patients participated in the study. Genotyping and haplotype analysis for 22 subjects were performed using short tandem repeat (STR) microsatellite polymorphism markers on 16 candidate genes and/or loci related to lipid metabolism. Two of the sixteen known candidate genes, APOA2 and USF1 were screened for mutation by direct DNA sequencing.</p><p><b>RESULTS</b>No linkage was found between the candidate genes/loci of APOA5, LIPI, RP1, APOC2, ABC1, LMF1, APOA1-APOC3-APOA4, LPL, APOB, CETP, LCAT, LDLR, APOE and the phenotype in this family. The two-point Lod scores (theta =0) were all less than-1.0 for all the markers tested. Linkage analysis suggested linkage to chromosome 1q23.3-24.2 between the disease phenotype and STR marker D1S194 with a two-point maximum Lod score of 2.44 at theta =0. Fine mapping indicated that the disease gene was localized to a 5.87 cM interval between D1S104 and D1S196. No disease-causing mutation was detected in the APOA2 and USF1 genes.</p><p><b>CONCLUSION</b>The above mentioned candidate genes were excluded as the disease causing genes for this family. The results implied that there might be a novel gene/locus for FHTG on chromosome 1q23.3-1q24.2.</p>

Disease gene screening of known loci in a Chinese family with autosomal dominant retinitis pigmentosa / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To map the disease-causing gene in a Chinese family with autosomal dominant retinitis pigmentosa.</p><p><b>METHODS</b>Twenty-seven micro-satellite markers were randomly selected from the region around the known loci of causative genes, and haplotypes were determined by ABI3100 genetic analyzer. Two-point linkage analysis was performed using MLINK.</p><p><b>RESULTS</b>The Lod score of each marker vs adRP was below 1.</p><p><b>CONCLUSION</b>The phenotype of this family may not be caused by mutation of the known disease-causing genes.</p>

Advances in molecular genetic study of myopia / 中华医学遗传学杂志

Myopia is an important cause of blindness, in which an image is focused in front of the retina. Genetic factors have been implicated in the pathogenesis of myopia. Based on the molecular genetic study, some genetic loci linked to myopia have been mapped, but no disease-causing gene has been identified. Here authors review the genetic study on myopia, including gene mapping and candidate gene screening.

A novel GJA8 mutation in a Chinese family with autosomal dominant congenital cataract / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutations in the gap junction protein alpha3/alpha8 gene (GJA3 or GJA8) in the Chinese family with autosomal dominant congenital cataract (ADCC).</p><p><b>METHODS</b>All subjects(5 family members and 100 unrelated control individuals)were undergone comprehensive ophthalmic examination, and genomic DNA was extracted from peripheral blood (5 mL). The exons and flanking introns of GJA3/GJA8 genes were amplified by polymerase chain reaction (PCR). Purified PCR products were then sequenced directly for screening disease-causing mutations.</p><p><b>RESULTS</b>Upon bidirectional sequence analysis, a G-->A transition at nucleotide 138 (c.138G>A)in exon 2 of GJA8 was found, resulting in synonymous mutation of glycine (GGG) to glycine (GGA). An additional G-->T transvertion at nucleotide 139 (c.139G>T) in exon 2 of GJA8, resulting in a missense mutation of asparagines (GAU) to tyrosine (UAU) at codon 47 (D47Y). These two alterations were not seen in all unaffected members and 100 unrelated control individuals. Bioinformatic analyses also showed that a highly conserved region was located at Asp47. Meanwhile no sequence variations for GJA3 were detected from the 3 affected members.</p><p><b>CONCLUSION</b>A novel disease-causing mutation (D47Y) of GJA8 gene in a Chinese family with ADCC is reported.</p>

Linkage analysis of one family with autosomal dominant high myopia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To map the high myopia gene in a Chinese family with autosomal dominant high myopia.</p><p><b>METHODS</b>A family with autosomal dominant high myopia in three generations was collected. Eighteen short-tandem-repeat markers on previously reported loci linked to high myopia were chosen for genotyping and two-point linkage analysis was carried out.</p><p><b>RESULTS</b>The spherical equivalent of affected individuals ranges from -6.00D to -20.00D and the genetic pattern is autosomal dominant. The LOD score was less than -1 in all 18 microsatellite markers, indicating that there was no linkage between these markers and the high myopia related genes in this family.</p><p><b>CONCLUSION</b>A novel myopia locus for high-grade myopia may exist in the kindred. Genome-wide scan will be needed to determine this novel locus.</p>