New X-linked mental retardation syndrome with the gene mapped tentatively in Xp22.3

X-linked mental retardation (XLMR) is genetically heterogeneous and clinically variable. We describe a new XLMR syndrome of severe mental retardation and multiple congenital anomalies. Two sisters have (with 3 different partners) 3 severely handicapped sons. In 2 cases, oligohydramnios and intrauterine growth retardation were noted. Common anomalies included a square-shaped face, high and broad forehead, frontal bossing, downward slant of palpebral fissures, hypertelorism, epicanthic folds, long philtrum, thin upper lip, and apparently low-set ears. One boy has bilateral microphthalmos and sclerocornea, and his cousin has atrophy of the optic nerve. All 3 patients are blind and have profound statomotor and mental retardation, seizures, and a grossly abnormal electroencephalographic pattern. Additional findings are short stature, delayed bone maturation, hydronephrosis, vesicorenal reflux, cryptorchidism, clinodactyly of the 5th fingers, and transverse palmar creases. The karyotype is normal (46,XY). Segregation analysis showed perfect coinheritance between the clinical phenotype and alleles at several loci in Xp22.3, whereas recombinants were identified with marker loci from Xp22.2-qter. Analysis of multiple informative meioses suggests that the disease locus maps in Xp22.3 distal to DXS16. © 1996 Wiley-Liss, Inc.     

Genomic structure of a human holocytochrome c-type synthetase gene in Xp22.3 and mutation analysis in patients with Rett syndrome

The human holocytochrome c-type synthetase (HCCS) gene is located on Xp22.3 and is one of the genes identified in a 450-Kb region deleted in the neurodevelopmental disorder microphthalmia with linear skin defects. Several other developmental disorders with or without a neurological phenotype have been linked to Xp22.3. This region of the X chromosome was also found to be concordant in patients with Rett syndrome (RTT)in previously performed exclusion mapping. Based on its chromosomal location and its role in the mitochondrial respiratory chain, we analyzed HCCS as a candidate gene for RTT. The genomic structure of this gene, which occupies an 11-Kb region and consists of seven exons, was determined. All intron-exon boundaries were sequenced and primers were designed for polymerase chain reaction (PCR) amplification of each coding exon. PCR-amplified products from genomic DNA isolated from 20 RTT patients were screened for mutations using heteroduplex analysis. No mutations were detected. The genomic characterization of this gene will allow us to perform mutation analysis for other inherited disorders linked to this region. Am. J. Med. Genet. 78:179–181, 1998. © 1998 Wiley-Liss, Inc.     

Contiguous gene syndrome due to an interstitial deletion in Xp22.3 in a boy with ichthyosis, chondrodysplasia punctata, mental retardation and ADHD

Microdeletions of Xp22.3 can result in contiguous gene syndromes, showing the variable association of apparently unrelated clinical manifestations such as ichthyosis, chondrodysplasia punctata, hypogonadotropic hypogonadism, anosmia, ocular albinism, short stature and mental retardation. We report on a boy with ichthyosis, dysmorphic features and mental retardation with ADHD. The patient was born at term after a pregnancy complicated by threatened abortion; decreased fetal movements and low estriol serum levels were reported during the last trimester. The boy was referred to us at the age of 13 years. He presented with aggressive and hyperactive behavior. He had dry hair, a flat face, bilateral lens opacities, a small nose with hypoplastic tip, alae nasi and nares, a high-arched palate with a very small cleft, mixed dentition with 7 unerupted permanent teeth, left sensorineural and right mixed hearing loss with a calcified plaque of the tympanic membrane, marked shortness of terminal phalanges of hands and feet, ichthyosis of trunk and limbs. The genomic interval between AFM248th5 and KAL1 was investigated. PCR analysis showed a deletion in Xp22.3, with the distal breakpoint between the marker AFM248th5 and PABX and the proximal one between DXS278 and KAL1. Array-CGH and FISH analysis confirmed the interstitial deletion (of about 5.5 Mb) and refined the breakpoints. We discuss the phenotype of our patient in relationship to the deleted segment and the possibility of mental retardation and ADHD genes in the region.     

Interstitial deletion in Xp22.3 is associated with X linked ichthyosis, mental retardation, and epilepsy

We describe monozygotic male twins with an interstitial deletion of Xp22.3 including the steroid sulphatase gene (STS). The twins had X linked ichthyosis, X linked mental retardation, and epilepsy. A locus for X linked mental retardation has been assigned to a region between STS and DXS31 spanning approximately 3 Mb. Recently the locus was further refined to an approximately 1 Mb region between DXS1060 and GS1. By PCR analysis of flanking STS gene markers in our patients we succeeded in narrowing down the locus to between DXS6837 and GS1.


Keywords: Xp22.3 deletion; X linked mental retardation; X linked ichthyosis; epilepsy; Rudd syndrome     

Localization of a gene for X-linked nonspecific mental retardation (MRX24) in Xp22.2–p22.3

Nonspecific X-linked mental retardation (MRX) includes several distinct genetic entities in which mental retardation is not associated with additional distinguishing physical changes. We report linkage data in a Spanish family with MRX, using polymorphic DNA markers distributed over the X chromosome. Two-point linkage analysis demonstrated close linkage between the MRX locus and DXS85 in Xp22.3 with a peak lod score of 2.28 at a Ø = 0.00. Analysis of multiple informative meioses suggested a localization of the MRX locus (MRX24) between DXS278 and DXS207. Multipoint linkage analysis resulted in a maximum LOD score of 2.45 at 3 cM proximal to DXS85, and allowed us to reject a localization of the MRX24 gene in all other regions from Xp21–Xqter. These findings localize the MRX24 gene in the chromosomal region Xp22.2–p22.3. © 1995 Wiley-Liss, Inc.     

精神分裂症易感基因

精神分裂症是一类遗传倾向性较高的多基因疾病.近年来,随着遗传学和分子生物学为主的多学科研究技术的快速发展,不断有新的易感基因报道;一些重要易感基因的生物学功能及其在该疾病发病机制中的作用研究也取得了一定进展.     

Short stature in a mother and daughter with terminal deletion of Xp22.3

Short stature in females is often caused by hemizygosity for the terminal portion of Xp due to monosomy X or a deletion. We report on a mother and daughter with short stature as sole phenotypic abnormality and deletion of bands Xp22.32-p22.33 demonstrated by classic and molecular cytogenetic analysis. In both individuals, the deleted X chromosome was late replicating. Molecular analysis suggested that the deletion is terminal and the breakpoint was localized between the STS and DXS7470 loci in Xp22.32. Chromosome analysis is often done on females with short stature to exclude Ullrich-Turner syndrome. Small deletions, terminal or interstitial, are easily missed by conventional cytogenetic investigation; thus molecular analyses are useful to detect those cases. © 1996 Wiley-Liss, Inc.     

Assignment of the human connexin43 gene,GJA1, to chromosome 6q22.3

Summary Connexin43 is one of connexin proteins which make up the intercellular gap junctions. Targeted null mutation of the mouse connexin43 gene has been reported to result in a cardiac malformation. Moreover, single-base mutations of the human homolog (GJA1) were identified in patients with laterality defects of the chest and abdominal organs, suggesting that connexin43 contributes to the determination of laterality during organogenesis. We mappedGJA1 to 6q22.3 by fluorescencein situ hybridization, using a bacterial artificial chromosome (BAC) clone that covered almost the entireGJA1-cDNA, as a probe.     

Léri-Weill syndrome as part of a contiguous gene syndrome at Xp22.3

We report on a mother and her 5-year old son, both with a terminal deletion of the short arm of the X chromosome. By molecular genetic analysis the breakpoint was located distal to steroid sulfatase gene. The boy manifested, due to nullisomy of this region, short stature (SHOX), chondrodysplasia punctata (ARSE), and mental retardation (putative mental retardation gene MRX 49). Short stature is present in mother and son, but both also had bilateral Madelung deformity, a key finding in the Léri-Weill syndrome.We discuss the phenotype in relationship to hitherto published cases with chromosomal aberrations and contiguous gene syndromes of Xp22.3. Am. J. Med. Genet. 83:367–371, 1999. © 1999 Wiley-Liss, Inc.     

Mental retardation locus in Xp21 chromosome microdeletion

Xp21 microdeletion syndrome is associated with variable size Xp21 deletions that usually include the glycerol kinase locus. The clinical phenotypes we studied in this chromosome region include: Xpter – Åland Island eye disease (AIED) -adrenal hypoplasia (AH) -glycerol kinase (GKD) -Duchenne muscular dystrophy (DMD) -retinitis pigmentosa (RP) -ornithine transcarbamylase (OTC) -centromere. In a compilation of 18 individuals in 14 families with the AH, GKD, and DMD loci deleted, 17 were male and all were developmentally delayed. In contrast, we report mentally retarded female carriers in two Xp21 deletion syndrome families with DMD, GKD, and AH in affected males. In the first family with normal karyotypes, a submicroscopic deletion was associated with DMD in the retarded male and with retardation in carrier females. In the second family an X chromosome with a cytogenetically deleted Xp21 distal to the OTC and RP genes segregated in the affected male and retarded female carriers. DNA analysis at the DMD locus verified the cytogenetic findings. This report of mental retardation in otherwise asymptomatic female carriers of Xp21 deletion classifies one form of mental retardation in females. © 1993 Wiley-Liss, Inc.     

具有凶杀行为的偏执型精神分裂症患者的心理防御机制

目的:了解具有凶杀行为的偏执型分裂症患者的心理防御机制。方法:采用防御方式问卷对具有凶杀行为的偏执型分裂症患者41例(凶杀组)、非凶杀行为的偏执型分裂症65例(病例对照组)及正常对照50例(正常对照组)进行测查比较。结果:凶杀组、病例对照组的不成熟心理防御机制因子评分均高于正常对照组(4.9±0.9,5.0±1.0/3.9±0.6,F=27.04,P=0.000),投射、被动攻击、分裂、退缩、躯体化六个条目评分也高于正常对照组(P<0.05,P<0.001),病例对照组中间型防御机制因子评分高于正常对照组(5.0±1.1/4.5±0.8,P<0.05),反作用形成、同一化条目评分高于正常对照组(5.0±1.4/4.1±1.4,4.9±2.6/3.3±2.0,P<0.01);凶杀组不成熟心理防御机制的被动攻击、中间型心理防御机制的反作用形成评分高于病例对照组(5.5±0.9/5.0±1.2,5.6±0.9/5.0±1.4,P<0.01)。结论:偏执型精神分裂症患者多采用不成熟型心理防御机制,凶杀偏执型分裂症患者更多地采用不成熟型心理防御机制的被动攻击和中间型心理防御机制的反作用形成。     

Localization of two X-linked mental retardation (XLMR) genes to Xp: MRX37 gene at Xp22.31-p22.32 and a putative MRX gene on Xp22.11-p22.2

MRX genes of 2 families with X-linked mental retardation (XLMR) were localized by linkage analysis. In family A, the gene was mapped to Xp22.31–p22.32, with significant LOD scores to various Xp22 markers within a distance of 6 Mb between DXS1223 and DXS1224. The MRX gene of this family was designated MRX37. In a mentally retarded female who is a carrier of the MRX37 gene, a random pattern of X inactivation was demonstrated. In family B, a positive LOD score, although not significant (< + 2), was found with the marker DXS1202 at Xp22.11–p22.2. © 1996 Wiley-Liss, Inc.     

Interstitial deletion of bands 11q21→22.3 in a three-year-old girl defined using fluorescence in situ hybridization on metaphase chromosomes

A 3-year-old girl has a de novo deletion of 11q21-22.3. The patient was studied because of minor anomalies, disproportionate short stature, and developmental delay. The deletion was first detected by conventional cytogenetic analysis and defined further by using chromosome 11–specific YAC clones by fluorescent in situ hybridization (FISH) on metaphase chromosomes. Three YAC clones, 11H7, 4A5, and IH4, were lacking from one of the patient's chromosome 11. Trigonocepahly, hypertelorism, apparently low-set ears, mild renal abnormality, and delay in speech development found in our patient are similar findings in other published interstitial deletion cases. Our study shows that a molecular cytogenetic approach is useful in defining the specific location and the extent of an interstitial deletion in cytogenetically difficult areas such as 11q. Am. J. Med. Genet. 86:416–419, 1999. © 1999 Wiley-Liss, Inc.     

中国人群中家族性精神分裂症与1号染色体的连锁分析

目的 探讨中国人群中家族性精神分裂症易感基因1号染色体的分子遗传学关系。方法 用基因组扫描的方法，选择了平均分布在1号染色体上的29个标记，对32个家族性精神分裂症家系样本进行易感基因扫描。结果 参数连锁分析结果,在隐性模型下，多点连锁在262.52cM位置得到最大异质性Lod分为1．70；非参数连锁分析结果，262.52cM位置处理到最大的多点非参数连锁分为1.71(P=0.046)首次是149.70cM位置处得到多点非参数连锁分为1.37(P=0.086)，分别对应于标记D1S206，D1S425位点的位置。结论 进一步支持在染色体1q上可能存在家族性精神分裂症的易感基因。     

Analysis of an interstitial deletion in a patient with Kallmann syndrome, X-linked ichthyosis and mental retardation

Contiguous gene syndromes are an interesting clinical phenomenon, resulting from interstitial or terminal deletions of several adjacent genes. The phenotype results in a combination of two or more monogenic disorders and relates clinical findings to corresponding genotypes. We present the case of a male patient with Kallmann syndrome (KS), X-linked ichthyosis (XLI) and X-linked mental retardation (MRX). He was referred at the age of 15.4 years for delayed puberty and obesity. He had a previous history of pyloric stenosis, bilateral orchidopexy and surgical correction of a pes equinovarus adductus. On physical examination, generalised ichthyosis and hypoplastic external genitalia were found. KS was evident with hypogonadotropic hypogonadism, hyposmia and a hypoplastic anlage of the olfactory tract in magnetic resonance imaging. Lipoprotein electrophoresis, and lack of steroid sulfatase and arylsulfatase-C activity in leucocytes confirmed XLI. DNA investigation established an interstitial deletion in Xp22.3 involving the Kallmann (KAL) gene, the steroid sulfatase (STS) gene and a putative mental retardation locus (MRX). The novel MRX locus maps to a 1-Mb region between DXS1060 and GS1.     

Xp11.2易位/TFE3基因融合相关性肾癌的临床病理学特点

目的 探讨Xp11.2易位/TFE3基因融合相关性肾癌的临床病理学特点.方法 对4例Xp11.2易位/TFE3基因融合相关性肾癌进行临床资料分析、组织学观察和免疫组化研究,并复习相关文献.结果 4例患者年龄自6～20岁,均具有腰痛的症状和较高的临床分期.肿瘤最大径2.5～10 cm,切面灰黄间灰红色.组织学上,肿瘤显示乳头状和腺泡状2种生长方式, 间质可见钙化.肿瘤细胞界限清楚,胞质淡红染至透亮,染色质呈泡状,核仁易见.4例肿瘤均弥漫高表达TFE3和CD10,不同程度表达CK、EMA和vimentin.结论 Xp11.2易位/TFE3基因融合相关性肾癌是最近被定义的一种罕见肿瘤,好发于年轻患者,预后较差.其诊断主要依靠特征性的组织病理学改变和免疫标记TFE3阳性.     

Xp22.3微缺失/微重复的研究进展

随着细菌人工染色体微珠标记技术(BACs-on-Beads ,BoBs)及基因芯片技术的应用,产前诊断中常会发现Xp22.3微缺失/微重复病例。由于其发生率较高,国内对Xp22.3微缺失/微重复的病理意义研究较少,本文针对Xp22.3微缺失/微重复的流行病学、产生机制、临床表型及产前诊断等研究进展进行了综述,为临床遗传咨询提供依据。     

精神分裂症遗传易感性研究进展

精神分裂症是人类最常见的精神疾患之一,属于复杂的多基因遗传性疾病。随着分子生物学技术和遗传学数据分析方法的进步,精神分裂症易感基因方面的研究也取得了一定的进展。本文就近年来国际上关于精神分裂症遗传易感性研究的一些成果进行综述,主要内容包括：(1)精神分裂症分子遗传学研究的基本策略与方法;(2)精神分裂症易感基因的全基因组扫描研究结果;(3)依据精神分裂症发病的三大假说,进行的候选基因研究的部分结果;(4)采用新型多位点联合作用分析方法,寻找精神分裂症的易感基因。     

Mental retardation in a boy with an interstitial deletion at Xp22.3 involving STS,KAL1, and OA1: Implication for the MRX locus

Although genotype-phenotype correlations in male patients with various types of nullisomy for Xp22.3 have assigned a locus for X-linked mental retardation (MRX) to an approximately 3-Mb region between DXS31 and STS, the precise location has not been determined. In this paper, we describe a 14 7/12 year old Japanese boy with mental retardation and an interstitial deletion at Xp22.3 involving STS, KAL1, and OA1, and compare the deletion map with that of previously reported three familial male patients with low-normal intelligence and a similar interstitial deletion at Xp22.3. The results suggest that the MRX gene is further localized to the roughly 1.5-Mb region between DXS1060 and DXS1139. © 1996 Wiley-Liss, Inc.