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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The majority of deletions of the short arm of chromosome 5 are associated with cri du chat syndrome (CdCS) and patients show phenotypic and cytogenetic variability. To perform a genotype-phenotype correlation, 80 patients from the Italian CdCS Register were analysed. Molecular cytogenetic analysis showed that 62 patients (77.50%) had a 5p terminal deletion characterised by breakpoint intervals ranging from p13 (D5S763) to p15.2 (D5S18). Seven patients (8.75%) had a 5p interstitial deletion, four (5%) a de novo translocation, and three (3.75%) a familial translocation. Of the remaining four patients, three (3.75%) had de novo 5p anomalies involving two rearranged cell lines and one (1.25%) had a 5p deletion originating from a paternal inversion. The origin of the deleted chromosome 5 was paternal in 55 out of 61 patients (90.2%). Genotype-phenotype correlation in 62 patients with terminal deletions highlighted a progressive severity of clinical manifestation and psychomotor retardation related to the size of the deletion. The analysis of seven patients with interstitial deletions and one with a small terminal deletion confirmed the existence of two critical regions, one for dysmorphism and mental retardation in p15.2 and the other for the cat cry in p15.3. Results from one patient permitted the cat cry region to be distally narrowed from D5S13 to D5S731. Furthermore, this study lends support to the hypothesis of a separate region in p15.3 for the speech delay.
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PMID:Clinical and molecular characterisation of 80 patients with 5p deletion: genotype-phenotype correlation. 1123 81

Microscopically visible distal 8p deletions have been associated with growth and mental impairment, minor facial anomalies, congenital heart defects, and behavioral problems. We report two cousins with mild retardation and behavioral problems, including inappropriate sexual behavior and pyromania. Familial learning difficulties on the grandfather's side incompatible with Mendelian inheritance prompted telomere screening, which detected a submicroscopic terminal 8p deletion of < 5.1 Mb. The cousins' mothers both carried a t(8;20)(p23;p13) balanced translocation. The frequently observed microcephaly in patients with microscopically visible deletions of 8pter is lacking in both cousins, suggesting that the gene(s) causing the microcephaly is centromeric to the deleted region. The absence of cardiac defects in the cousins confirms the more proximal location of gene(s) causing these abnormalities in other reported cases with microscopically visible 8pter deletions and supports involvement of the GATA4 gene. Moreover, the current cases predict the presence of a putative gene(s) involved in behavior in the most telomeric 5.1 Mb of the p-arm of chromosome 8. This first clinical report of a submicroscopic subtelomeric 8p deletion gives more insight into the so-called 8p- syndrome and demonstrates the difficulty in making a clinical diagnosis for a submicroscopic 8pter deletion in an individual patient with mental retardation.
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PMID:Submicroscopic 8pter deletion, mild mental retardation, and behavioral problems caused by a familial t(8;20)(p23;p13). 1125 99

We report on the multistep progression to the correct genetic diagnosis in an apparently new syndrome of mental retardation and multiple congenital anomalies, including hypogenitalism and polymicrogyria. We had previously reported it as an X-linked condition affecting four members (three males and one female) of a family [Zollino et al., 1992: Am J Med Genet 43:452-457]. Two of the four patients, both males, presented with a brain abnormality that was initially described as pachygyria, while the remaining two (one male and one female) did not. Our present study includes a clinical follow-up on the patients, neuroradiological reexamination of one patient, X linkage studies and X inactivation analyses, and finally molecular cytogenetics, which allowed us to establish definitely the genetic causes of the condition. After the detection of a subtle t(1;12)(q44;p13.3) balanced translocation in healthy carriers, two unbalanced segregation products were observed in different patients, resulting in 1q44qter monosomy and 12p13.3pter trisomy in patients with polymicrogyria and severe psychomotor delay, 12p13.3pter monosomy and 1q44qter trisomy in the other two patients without polymicrogyria, with less severe mental retardation and less distinctive physical anomalies. Thus, this condition is no longer to be considered X-linked, but the result of cryptic autosomal imbalance. Furthermore, this study identified an approximately 14 Mb interval in 1q44qter pathogenetically related to polymicrogyria.
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PMID:Cryptic t(1;12)(q44;p13.3) translocation in a previously described syndrome with polymicrogyria, segregating as an apparently X-linked trait. 1254 42

Zimmermann-Laband syndrome (ZLS) is a rare disorder characterized by gingival fibromatosis, abnormalities of the nose and/or ears, and absence or hypoplasia of nails or terminal phalanges of hands and feet. Other more variable features include hyperextensibility of joints, hepatosplenomegaly, mild hirsutism, and mental retardation. The genetic basis of ZLS is unknown; autosomal dominant inheritance has been suggested. We report an apparently balanced chromosomal aberration, 46,XX, t(3;8)(p13-p21.2;q24.1-q24.3), in a family with an affected mother and daughter. Using fluorescence in situ hybridization with BAC clones, we refined the breakpoints to 3p21.2 and 8q24.3 and, thereby, narrowed down both breakpoint regions to approximately 1.5 Mb. Our data provide additional support to the assumption that ZLS follows autosomal dominant inheritance. The 3;8 translocation described here represents a powerful resource to identify the causative gene for ZLS that maps most likely to one of the breakpoints.
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PMID:Zimmermann-Laband syndrome associated with a balanced reciprocal translocation t(3;8)(p21.2;q24.3) in mother and daughter: molecular cytogenetic characterization of the breakpoint regions. 1259 95

In this report we describe the case of an 11-year-old male with autism and mental retardation, presenting a tetrasomy of chromosome 3q. Cytogenetic analysis showed a mosaic for an unbalanced karyotype consisting of mos46,XY,add(12)(p13.3)(56)/46,XY(45). FISH using WCP and subtelomeric probes identified the extra material on 12p to be an inverted duplication of the distal segment of chromosome 3q. Anomalies in chromosome 3q have not been previously described in association with autism, although association with psychomotor delays and behavior problems has been frequently reported and are here further discussed. This chromosomal 3q segment is therefore likely to include genes involved in specific neurodevelopment pathways, and further analysis of the region is warranted for the identification of the molecular alterations that lead to the autistic features described.
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PMID:Partial tetrasomy of chromosome 3q and mosaicism in a child with autism. 1275 57

Cutis marmorata telangiectatica congenita (CMTC) is a rare cutaneous disorder. More than one half of the patients with CMTC have additional extra-cutaneous associated congenital anomalies. A subset of patients with CMTC have macrocephaly, the M-CMTC syndrome. This is a report on a patient with the M-CMTC syndrome and a de novo translocation t(2;17)(p11;p13). The etiology and pathology of the M-CMTC syndrome is unknown. Suggestions for the cause for M-CMTC include the occurrence of a new dominant mutation in a single gene, deletion of multiple contiguous genes at a level beyond the resolution of conventional karyotyping and chromosomal mosaicism. This patient did not have chromosomal mosaicism, however he had a translocation. It can be postulated that in the present patient the translocation breakpoints disrupted one or more genes entailing skin lesions but also other features: mental retardation, macrocephaly and facial dysmorphia.
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PMID:Macrocephaly-cutis marmorata telangiectatica congenita: report of a patient with a translocation. 1287 11

Weill-Marchesani syndrome (WMS) is a rare condition characterized by short stature, brachydactyly, joint stiffness, and characteristic eye abnormalities including microspherophakia, ectopia of lens, severe myopia, and glaucoma. Both autosomal recessive (AR) and autosomal dominant (AD) modes of inheritance have been described for WMS. A locus for AR WMS has recently been mapped to chromosome 19p13.3-p13.2 while mutation within the fibrillin-1 gene (15q21.1) was found in one AD WMS family. In order to answer the question of whether or not genetic heterogeneity could be related to a clinical heterogeneity, we reviewed 128 WMS patients from the literature (including 57 AR, 50 AD, and 21 sporadic cases), with a particular attention to clinical features. Statistical analyses using Fischer exact test were used to compare the proportions of 12 clinical parameters between AR and AD patients. There was no significant difference between both groups for myopia, glaucoma, cataract, short stature, brachydactyly, thick skin, muscular build, and mental retardation. Significant results were found for microspherophakia (94% in AR, 74% in AD, Fischer 0.007), ectopia lentis (64% in AR, 84% in AD, Fischer 0.016), joint limitations (49% in AR, 77% in AD, Fischer 0.010), and cardiac anomalies (39% in AR, 13% in AD, Fischer 0.004). Nevertheless, we failed to distinguish AR from AD inheritance in individual cases. These results support the clinical homogeneity but the genetic heterogeneity of WMS.
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PMID:Clinical homogeneity and genetic heterogeneity in Weill-Marchesani syndrome. 1459 50

In general, carriers of paracentric inversions are phenotypically normal, although individual reports describe like occurrence of infertility, miscarriages and mental retardation in inversion carriers. We present a family with paracentric inversion of 1p [karyotype: 46,XY/XY, inv(1)(p13.2p36.2)] in 7 of the 12 investigated family members. The index patient, a four year-old boy was referred for motor and mental retardation. The possible relationship between the paracentric inversion and the MR/MCA syndrome in the index patient of this family is briefly discussed.
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PMID:Paracentric inversion in the short arm of chromosome 1. Report of a family and review of the literature. 1473 16

The use of subtelomeric FISH probes has greatly supplemented conventional chromosome analysis in detecting cryptic anomalies in patients with mental retardation (MR), dysmorphic features, and congenital malformations. We report a 3-month-old boy who was diagnosed with ambiguous genitalia, dysmorphic features, and developmental delay. Standard chromosome studies on blood revealed a chimeric karyotype of 46,XY,t(4;5)(q31.1;q14)[46]/46,XX[4]. The boy had intra-abdominal gonads that were testicular in origin by biopsy. Multiple dysmorphic features, marked hypotonia, developmental delay, poor growth, and relative macrocephaly were noted on physical exam. His 2.5-year-old sister also presented with hypotonia, developmental delay, relative macrocephaly, and similar dysmorphic stigmata. In addition, she was diagnosed with several internal malformations. Her karyotype was 46,XX. Due to the striking phenotypic similarity, subtelomeric FISH studies were initiated in the siblings. In addition to the known balanced karyotypic abnormalities, the boy was found to have a derivative chromosome 5 with a 5pter deletion and a 17pter duplication. This cryptic abnormality was also detected in his sister. Chromosome analysis of the father revealed a subtle balanced t(5;17)(p15.31;p13.1) which was confirmed by subtelomeric FISH, whereas the mother's chromosome complement was normal. This familial constellation illustrates the usefulness of subtelomeric FISH in the diagnosis of cryptic chromosome abnormalities in patients for whom conventional karyotype does not disclose findings sufficient to explain the observed phenotypic anomalies.
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PMID:Unbalanced cryptic 5p deletion/17p duplication identified by subtelomeric FISH in a family with a boy with chimerism and a balanced t(4;5). 1475 72

Unbalanced changes of chromosomes with loss or extra genetic material often cause changing phenotype. The main characteristics unbalanced karyotype involves mental retardation and numbers of anomalies, especially if the change involves autosoms. In this paper child with retard development and de novo translocation between chromosome 1 and chromosome 16 was described. Cytogenetics survey was carried out to establishing possible cause in relation with retard development and it involved standard cytogenetics method and method of differential staining (G-banding) that enables identification of certain structural rearrangement of chromosomes. Chromosome aberration was translocation of part of p arm of chromosome 1 on p arm of chromosome 16, that is, it presents abnormal karyotype 46, XX, t(1;16)(p13;p13) that might be one of the cause of retard development of child.
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PMID:[Unusual chromosome translocation 46, XX, t(1;16) (p13;p13) as a possible cause of retarded development of carrier]. 1552 83


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