Objective To review the research progress in relationship between hereditary diffuse gastric cancer (HDGC) and CDH1 gene. Methods Literatures on HDGC which were published in recent years were collected and analyzed. Results Aberrant CDH1 gene is significantly correlated with HDGC: mutations of CDH1 exons play the most important role in pathogenesis of HDGC. Screening CDH1 gene mutation is useful for diagnosis of HDGC as well as the treatments. Alterations of CDH1 other than exon mutation, such as intron mutation, gene promoter methylation and single nucleotide polymorphism may result in downregulation of the gene expression. Further study should be done to confirm the roles of these alterations. Conclusions Alterations of CDH1 gene are significantly associated with the pathogenesis of HDGC. Detecting alterations of CDH1 gene are important for diagnosis and management of HDGC as well as to get insights of the pathogenesis of the disease.
Objective To find the new mutations of Leber's hereditary optic neuropathy (LHON). Methods Two LHON families were enrolled in this study. The probands and all maternal members in this two families were underwent ophthalmologic examinations. The ages of probands were seven and 14 years old respectively. A total of 358 healthy adults were enrolled in this study as control group. The genomic DNA from whole blood of participants were extracted. The entire mitochondrial genome of probands were PCR amplified and sequenced in 24 overlapping fragments using primers as designed. At the same time, the mtDNA of maternal relatives and 358 controls were also detected. Fourteen primate species were selected from GenBank to analyzed the phylogenetics of mitochondrial sequence. Results There was no ND4 G11778A, ND1 G3460A, ND6 T14484C mutational site in all maternal members. Molecular analysis of mtDNA in this two families identified the homoplasmic tRNAGluA14683G mutation and distinct set of variants belonging to the Asian haplogroup F1a1 and G2. The site was at theTpsi;C stem oftRNAGlu and extremely conserved among 14 primate species. It was anticipated that the A14683G increased the highly conserved C-G basepairing. Furthermore, the A14683G was absence in control group. Conclusion The tRNAGluA14683G mutation is likely a new mutation associated with LHON.
ObjectiveTo identify 3 the disease-causing genes and mutations of Leber congenital amaurosis (LCA), and to study the correlation of phenotype and genotype. MethodsA retrospective study. Four LCA patients and seven family members who were diagnosed by eye examination in Ning Xia Eye Hospital of People's Hospital of Ningxia Hui Autonomous Region from January to December 2021 were included in the study. Four patients were from 3 unrelated families. Detailed collection of medical history and family history were received. Related ophthalmologic examination were collected and genomic DNA was extracted from peripheral blood. Whole-exome sequencing method was used for genetic diagnosis. The identified variant was confirmed with Sanger sequencing. Potential pathogenic mutation was analyzed using software and conserved domain analysis and performed co-separated analysis between the family member and the proband. ResultsOf the 4 patients, 1 patient was males and 3 patients were females; the age was from 4 to 18 years. Nystagmus were seen in 3 cases, finger pressing eyes and night blindness was seen in 1 cases; electroretinogram showed 4 cases of extinction or near extinction. The foveal reflection was visible in all eyes, and there was no obvious abnormality in the peripheral retina. One eye had strong reflection signal with raised ellipsoid in macular area; two eyes had weak reflection signal faintly visible between retinal layers; 1 eye had increased blood vessel branches, peripheral retinal non-perfusion area with capillary leakage; annular strong autofluorescence in macular area 4 eyes. No obvious abnormality was found in the phenotypes of family members. Genetic testing showed that the proband of pedigree 1 (Ⅱ-1) was found a homozygous missense mutation in c.640A>T (p.C214S) (M1) of PRPH2 gene. The proband of pedigree 2 (Ⅱ-2) was found compound heterozygous mutation in c.1256G>A(p.R419Q) (M2) and c.1A>C (p.M1L) (M3) of TULP1 gene. The proband 3 (Ⅱ-1) and her sister (Ⅱ-2) were both found compound heterozygous mutation in c.1943T>C (p.L648P) (M4) and c.380C>T (p.P127L) (M5) of GUCY2D gene. The parents and sister (Ⅱ-1) of the proband in family 2 and the parents of the proband in family 3 were all carriers of the corresponding heterozygous variant. M1, M3, M4, M5 were novel mutations and unreported. The genotype and disease phenotype were co-segregated within the family. According to the analysis of pedigree and genetic testing results, all 3 families were autosomal recessive inheritance. The amino acid conservation analysis found that M1, M2, M3, M4, and M5 were highly conserved among species. The results of bioinformatics analysis were all pathogenic variants. ConclusionsPRPH2 gene M1, TULP1 gene M3, and GUCY2D gene M4, M5 were novel mutations and not been reported in the literature and database. This research expanded the gene mutation spectrum of LCA. The patients with LCA have available characterristics, including onset age, varying ocular fundus and severe visual impairment.
ObjectiveTo observe clinical phenotypes and analyze the pathogenic genes of Leber congenital amaurosis (LCA). MethodsA retrospective clinical study. From 2019 to 2020, 2 patients diagnosed with LCA by genetic testing in Tianjin Medical University Eye Hospital and their 6 unaffected family members were enrolled in the study. Two patients were from 2 unrelated families, both were probands. The patient's medical history was inquired in detail, slit lamp microscopy, ultra-widefield fundus photography, autofluorescence, and flash visual evoked potential (F-VEP) were performed. Peripheral vein blood (3-5 ml) was collected and genomic DNA was extracted from all study subjects. A total of 381 pathogetic genes associated with inherited retinal diseases, were selected by targeted exome sequencing capture strategy. Sanger sequencing was used to verify suspected pathogenic mutations. Candidate pathogenic mutations were identified after bioinformatics analysis. Sanger sequencing, real-time quantitative polymerase chain reaction and family co-identification were used to confirm the final mutations. ResultsTwo patients were male, aged 3 and 27 years. One case had vision loss in both eyes, accompanied by nystagmus and acupressure eye sign since childhood. The clinical hallmark of the proband (F1-Ⅱ-3) in F1 includes clearly boundary of optic disc, normal retinal blood vessels and macular fovea. The implied period of the maximum forward wave in both eyes of F-VEP was roughly normal, and its amplitude decreased significantly. The phenotype of the proband (F2-Ⅱ-1) in F2 includes optic nerve head pallor, bone-spicule intraretinal pigmentation, “gold-foil maculopathy”, retina patchy hypo-autofluorescence in both eyes. There was no abnormal phenotype in the eyes of the family members. According to the genetic diagnosis, the proband (F1-Ⅱ-3) carried the GUCY2D gene c.835G>A (p.D279N) (M1) and exon 9-19 deletion (M2) compound heterozygous mutations, in which M1 was derived from healthy mother and M2 was derived from healthy father. The proband (F2-Ⅱ-1) carried CRB1 gene c.1576C>T(R526X) (M3) and c.1522T>C (C508R) (M4) compound heterozygous mutations, in which M3 from the healthy father, M4 from the healthy mother. M2 and M4 were novel mutations. ConclusionGUCY2D gene mutations lead to LCA1 type in the F1 family, CRB1 gene mutations lead to LCA8 type in the F2 family; there are significant different phenotypes caused by different pathogenic genes.
Objective To detect and analyse the mutations in rhodopsin gene of members in a family affected by autosomal dominant retinitis pigmentosa (ADRP). Methods Using the polymerase chain reaction (PCR), we amplified exon 1-5 of rhodopsin gene in patients with ADRP,and analyzed it with direct sequence measuement. Results The Gly-182-Asp mutation in the rhodopsin gene was detected in most of affected members of this ADRP family, but no mutation was detected in two affected members and the control ones. Conclusion We cannot regard the Gly-182-Asp mutation in the rhodopsin gene as the pathagenic factor of the ADRP family. It is likely there is a new gene next to the rhodopsin gene. (Chin J Ocul Fundus Dis, 2002, 18: 256-258)
ObjectiveTo report the clinical findings and RS1 gene mutation analysis of a Chinese family with X-linked juvenile retinoschisis (XLRS). MethodsThe pedigree of this XLRS family was studied. Nine individuals (10 eyes of 6 males, 6 eyes of 3 females), including the proband, received ocular examination, fundus photography and optical coherence tomography (OCT). Direct DNA sequencing of the 6 exons of RS1 gene was used to detect the RS1 mutation in 12 family members. ResultsThe present pedigree included 15 members of three generations. Among them, 5 male members were diagnosed with XLRS. The retina of other 4 family members were normal, including 1 male (2 eyes) and 3 females (6 eyes). Visual acuity of these 5 patients ranged from hand movement to 0.5 and both eyes of them were involved. The age when visual acuity begins to decrease was all less than 10 years. Fundus color photographic examination showed macular radial cystoid retinoschisis and retinoschisis of the peripheral retina. OCT images showed retinoschisis in macular regions (8 eyes) or peripheral retina (6 eyes). Genetic testing showed that 1 male had no mutation in RS1 gene (p.Gly109Val). All 5 patients had a point mutation (c.326G>T) at exon 4 of RS1 gene, which cause the 109th amino acid changed from glycine to valine in the RS1 protein. A 3-year-old kid also had this mutation. The 3 females with normal retina had heterozygous mutations of Gly109Val, so they are the mutation carriers. ConclusionThe novel p.Gly109Val mutation is the causing mutation in this Chinese family with X-linked juvenile retinoschisis.
Objective To analyze the new primary mutation in Chinese people with Leberprime;s hereditary optic neuropathy (LHON). Methods Genomic DNA was collected from 260 suspected LHON patients and 100 normal healthy persons. The mitochondria DNA mutation at nucleotide position (NP) 15257 and the hot spot (14452-14601 bp) of ND6 gene which include the mutations at NP (14482, 14498, 14568, 14596, 14495, and 14459) were screened by using polymerase chain reaction (PCR), heteroduplex-single strand conformation polymorphism (HA-SSCP) and restriction fragment length polymorphism (RFLP) analysis and sequencing. Primary mutation spectrum of Chinese race was analyzed. Results Eight kinds of polymorphism of mitochondria DNA were found in 260 suspected LHON patients and 100 normal healthy persons, including NP 14488C, 14518G, and 14617G which hadnrsquo;t been reported (http://www.mitomap.org/). No mutation at NP 15257, 14482, 14498, 14568, 14596, 14495, and 14459 was found. Conclusion The NP 15257A may not be the primary mutation in Chinese. Because of the race difference, 14452-14601 bp in ND6 gene may not be the hot spot in Chinese patients with LHON, and other hot spots may exist. (Chin J Ocul Fundus Dis, 2006, 22: 82-85)
Objective To observe the molecular genetic characteristics of seven Chinese families with Leberprime;s hereditary optic neuropathy (LHON). Methods Ophthalmologic examinations were performed on seven probands, maternal members from seven Chinese families and 134 healthy controls. There were two LHON patients in seven Chinese families except probands. The entire mitochondrial genome was amplified using 24 pairs of oligonucleotide primers with overlapping fragments.The mutational site was analyzed through comparison of the Results and Cambridge reference sequence. The penetrance of mutation site was calculated and the haplotype was analyzed. Results Molecular analysis of mitochondrial DNA (mtDNA) in these pedigrees revealed the absence of three common LHON associated with ND4 G11778A, ND1 G3460A and ND6 T14484C mutations. The ND1 T3394C mutation in probands and other matrilineal relatives was present in four out of 134 Chinese healthy controls. Strikingly, these families exhibited very low penetrance of visual impairment. The penetrance was 12.50%, 22.22%, 16.76%, 6.25%, 9.09%, 11.11% and 28.57%. The Results of phylogenetic tree analysis of submitochondrial haplotype showed that these mtDNA polymorphism sites belong to the Asian haplogroups M9, M9, M, D4, M, M9 and M9. Conclusions T3394C mutation exists in seven Chinese LHON pedigrees, and the penetrance was ranged from 6.25% to 28.57%. The patients have different clinical manifestations.
ObjectiveTo observe the clinical features of patients over 30 years old with Leber hereditary optic neuropathy (LHON). MethodsNine male LHON patients (18 eyes) were enrolled in this study. The patients aged from 34 to 56 years old, with an average age of (45.22±6.91) years. The course of the disease ranged from 7 days to 21 months, with a mean course of 5 months. Visual acuity, slit lamp microscope, chromoptometry, direct ophthalmoscope and fundus photography were measured for all patients, visual field examined for 6 patients (11 eyes). Mitochondrial DNA mutation was analyzed. The visual acuity was followed-up for 12 months. ResultsSeven of the 9 patients (77.78%) had family history. Five patients (55.56%) had both eyes involved simultaneously, and 4 patients (44.44%) had the eyes involved at different time. Three patients (33.33%) had sudden visual loss, and 6 patients (66.67%) had gradual visual loss. The visual acuity was light perception in 1 eye (5.55%), finger counting in 3 eyes (16.67%), 0.01-0.1 in 7 eyes (38.89%), 0.12-0.3 in 3 eyes (16.67%), equal or greater than 0.4 in 4 eyes (22.22%). Sixteen eyes (88.88%) had normal light reflex, 1 eye (5.55%) had no light reflex, and 1 eye (5.55%) had relative afferent papillary defect. Eight eyes (44.44%) had normal optic disk, 3 eyes (16.67%) had blurred optic disc border and disc telangiectasia, 7 eyes (38.89%) had pale disc and clear boundary. Among 11 eyes underwent visual field examination, 9 eyes (81.82%) had central or paracentral scotoma and 2 eyes (18.18%) had visual field narrowing. Among 9 patients, there were 7 patients (77.78%) with G11778A mutation, 1 patient (11.11%) with G11696A mutation, and 1 patient (11.11%) with T14484C mutation. In the last follow-up, the visual acuity was light perception in 1 eye (5.55%), finger counting in 4 eyes (22.22%), 0.01-0.1 in 6 eyes (33.33%), 0.12-0.3 in 3 eyes (16.67%), equal or greater than 0.4 in 4 eyes (22.22%).The visual acuity was improved in 9 eyes (50.00%), stable in 7 eyes(38.89%), and decreased in 2 eyes (11.11%). ConclusionLHON patients (older than 30 years) are more common in men, mostly with normal light reflex, central or paracentral scotoma and G11778A mutation.
ObjectiveTo observe the clinical manifestation and gene mutation of a pedigree with Sorsby fundus dystrophy (SFD). Methods Ten members in 3 generations of a pedigree with SFD were included in this study. Four patients were observed in the pedigree, including 2 females and 2 males. All 10 members underwent comprehensive ophthalmic examinations, including best-corrected visual acuity, intraocular pressure, slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus color photography and spectral domain optical coherence tomography. Genomic DNA was extracted from peripheral venous blood which was collected from all the members. Relevant exons of ocular diseases were detected by the next generation sequencing method from the proband. The other members underwent Sanger verification. Results Among the four patients, fading eyesight was appeared at their 44, 46, 47 and 40 year-old respectively. The two male patients had bilateral morbidity, and the two female patients had monocular symptoms. DNA sequencing results showed that the proband, other 3 patients and 2 members from the Ⅲ generation had heterozygous mutation of TIMP3 gene in exon 5. The amino acid encoded by TIMP3 gene No.204 codon changed from serine to cysteine (TIMP3:NM_000362:Exon5:c.A610T/p.S204C). CoclusionsThe invasion time of all the patients in this pedigree is after their 40 year-old. Heterozygous mutation at c.610A＞T (p.S204C) in TIMP3 gene is the causative gene of SFD in this pedigree.