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

Recently we reported two sibs, brother and sister, with a new multiple congenital anomalies/mental retardation (MCA/MR) syndrome characterized by mild to moderate psychomotor delay, Robin sequence, distinctive facial appearance, and brachydactyly. We have subsequently observed a similar pattern of anomalies in two unrelated patients who also showed additional clinical findings. This new observation supports the existence of a new syndrome and expands the phenotypic spectrum of the condition.
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PMID:Mental retardation, Robin sequence, and brachydactyly: further confirmation of a new syndrome. 1505 87

Inborn defects of cholesterol biosynthesis are a group of metabolic disorders presenting with mental retardation and multiple congenital anomalies (MCA/MR syndromes). Functional and structural liver involvement has been reported as a rare (2.5-6%) complication of the Smith-Lemli-Opitz syndrome (SLOS) and it has not been fully characterized. Here, we report on a long-term follow-up study of four patients with SLOS, and one case with lathosterolosis who presented with liver disease and underwent an extensive diagnostic work-up. Reports of liver involvement in cholesterol biosynthesis defects are reviewed. Two main different patterns of liver involvement emerged: progressive cholestasis, and stable isolated hypertransaminasemia. In our series, the first pattern was found in two patients with SLOS and one with lathosterolosis, and the second in two SLOS cases. Cholestasis was associated with early lethality and normal serum gamma-glutamyl-transferase (GGT) levels in SLOS, while possible prolonged survival and high GGT levels were seen in lathosterolosis. Hepatic fibrosis was present in both conditions. Liver biopsy performed in one of our SLOS patients with isolated hypertransaminasemia, showed only mild hydropic degeneration of the hepatocytes. The presence of liver involvement in 16% of the SLOS patients diagnosed at our Center suggests that this complication might have been underestimated in previously reported cases, possibly overshadowed by the severity of multiple malformations. Fetal hepatopathy, cholestasis, and isolated hypertransaminasemia can occur also in other disorders of cholesterol biosynthesis, such as mevalonic aciduria, desmosterolosis, Conradi-Hunermann syndrome, Greenberg dysplasia, and Pelger-Huet homozygosity syndrome. This group of inherited disorders should be considered in the differential diagnosis of patients presenting with liver disease associated with developmental delay and/or multiple malformations. Periodic liver function evaluations are recommended in these patients.
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PMID:Characterization of liver involvement in defects of cholesterol biosynthesis: long-term follow-up and review. 1558 Jun 35

Kabuki syndrome (KS) is a rare MCA/MR syndrome with an estimated frequency of 1/32 000 in Japan. This syndrome is characterized by postnatal growth retardation, distinctive facial features, dermatoglyphic anomalies, skeletal dysplasia, and mental retardation. The molecular basis of KS remains unknown. Recently, Milunsky and Huang reported on six unrelated patients with a clinical diagnosis of KS and an 8p22-8p23.1 duplication using comparative genomic hybridization and BAC-FISH studies. Also, they suggested that a paracentric inversion may contribute to the occurrence of KS. In the present study, 24 patients with a clinical diagnosis of KS based on Niikawa-Kuroki criteria have been collected. They were tested for the presence of an 8p duplication using the same clones as described by Milunsky and Huang. Our results do not confirm the previously described association between KS and an 8p22-8p23.1 duplication.
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PMID:Failure to detect an 8p22-8p23.1 duplication in patients with Kabuki (Niikawa-Kuroki) syndrome. 1577 Feb 28

In recent years, subtelomeric rearrangements have been identified as a major cause of multiple congenital anomalies/mental retardation syndromes. Currently, more than 2,500 individuals with mental retardation have been tested and reported in whom subtelomeric rearrangements were detected ranging from 2% to 29%. Therefore, subtelomeric FISH analysis is indicated as a second tier test after high-resolution G-banding analysis in patients with otherwise unexplained developmental delay/mental retardation and/or multiple congenital anomalies. We describe a patient and her three maternal female cousins, all showing an undiagnosed MCA/MR syndrome, associated with the same complex subtelomeric rearrangement. Subtelomeric FISH testing performed between 3(1/2) and 18 years after the initial karyotype showed, in all four patients, distal trisomy 3q and distal monosomy 10q as follows: 46,XX,ish der(10)t(3;10)(q29;q26.3)mat(D10S2488+,D10S2490-, D3S1272+,D10Z1+). Parental subtelomeric FISH analysis showed that the proposita's mother and three of four brothers and one of two sisters had a cryptic balanced 3:10 telomere translocation. The three brothers with the balanced translocation were father to one each of the three proband's cousins. All four affected girls showed a similar phenotype with pre/postnatal growth retardation, microcephaly, severe developmental delay/mental retardation, poor/absent speech, and a distinct pattern of malformation. On examination there were coarsening of facial features with low fronto-temporal hairline; thick eyebrows; bilateral epicanthal folds; hypertelorism; prominent nose with squared nasal root and narrow alar base; low-set posteriorly rotated large ears with a prominent anthelix; high arched palate; prominent chin; hands/feet brachydactyly; bilateral squint; hypotonia; and muscle hypotrophy. A slow overall improvement was seen in all patients over time. To our knowledge, this complex subtelomeric rearrangement in our patients has never been reported so far. Monosomy 10q has recently been described either isolated or as part of a complex rearrangement involving telomeres other than the 3q. Trisomy 3q29 has not yet been reported, but our patients resembled cases with 3q26 trisomy suggesting that the critical region of duplication for this phenotype is in 3q29.
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PMID:Familial complex 3q;10q rearrangement unraveled by subtelomeric FISH analysis. 1635 44

The evaluation of multiple congenital abnormalities and/or mental retardation (MCA/MR) is always a challenge to clinicians. The recognition of specific physical or behavioral characteristics can vastly improve diagnostic yield. Chromosomal abnormalities account for a high percentage in the etiology of MCA/MR. In this study, frequency of chromosomal abnormalities was 4.81% of 457 patients. Chromosomal abnormalities and polymorphisms were detected in 65 (14.21%) (structural and numerical chromosomal abnormalities in 22 patients and polymorphisms in 43) of 457 MR and/or MCA patients. Our results show that chromosomal abnormalities contribute much to the causation of multiple malformations and/or MR. It is essential that fluorescence in situ hybridization (FISH) be used in conjunction with standard methods in order to maximize obtainable information for better management of patients with MR and/or MCA.
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PMID:Chromosomal abnormalities in 457 Turkish patients with MCA/MR. 1684 12

Molecular karyotyping has revealed that microdeletions/duplications in the human genome are a major cause of multiple congenital anomalies associated with mental retardation (MCA/MR). The identification of a de novo chromosomal imbalance in a patient with MCA/MR is usually considered causal for the phenotype while a chromosomal imbalance inherited from a phenotypically normal parent is considered as a benign variation and not related to the disorder. Around 40% of imbalances in patients with MCA/MR in this series is inherited from a healthy parent and the majority of these appear to be (extremely) rare variants. As some of these contain known disease-causing genes and have also been found to be de novo in MCA/MR patients, this challenges the general view that such familial variants are innocent and of no major phenotypic consequence. Rather, we argue, that human genomes can be tolerant of genomic copy number variations depending on the genetic and environmental background and that different mechanisms play a role in determining whether these chromosomal imbalances manifest themselves.
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PMID:Molecular karyotyping of patients with MCA/MR: the blurred boundary between normal and pathogenic variation. 1712 4

The previously undescribed combination of esophageal atresia, hypoplasia of the zygomatic complex, microcephaly, cup-shaped ears, congenital heart defect, and mental retardation was diagnosed in two siblings of different sexes, with the brother being more severely affected. The mother presented with zygomatic arch hypoplasia of the right side only. We discuss major differential diagnoses: Goldenhar, Feingold, CHARGE, and Treacher Collins syndromes show a few overlapping clinical features, but these diagnoses are unlikely as the clinical findings are unusual for Goldenhar syndrome and mutational screening of the MYCN, the CHD7, and the TCOF1 genes did not reveal any abnormalities. Autosomal recessive oto-facial syndrome, hypomandibular faciocranial dysostosis, and Ozkan syndromes were clinically excluded. A microdeletion 22q11.2 was excluded by FISH analysis, a microdeletion 2p23-p24 by microsatellite analyses, a subtelomeric chromosomal aberration by MLPA, and a small genomic deletion/duplication by CGH array. As X-inactivation studies did not show skewed X-inactivation in the mother, we consider X-chromosomal recessive inheritance of this condition less likely. We discuss autosomal dominant inheritance with variable expressivity or mosaicism in the mother as the likely genetic mechanism in this new multiple congenital anomaly/mental retardation (MCA/MR) syndrome.
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PMID:Esophageal atresia, hypoplasia of zygomatic complex, microcephaly, cup-shaped ears, congenital heart defect, and mental retardation--new MCA/MR syndrome in two affected sibs and a mildly affected mother? 1749 18

Cohen syndrome is an autosomal recessive, multiple congenital anomalies/mental retardation (MCA/MR) syndrome, caused by a mutation in the COH1 gen, localized on chromosome 8q22. COH1 encodes a transmembrane protein of 4.022 amino-acids with a presumed role in vesicle-mediated sorting and intracellular protein transport. Clinical features are non progressive psychomotor retardation and microcephaly, characteristic facial features, retinal dystrophy, and intermittent neutropenia. Examination of the long-term evolution of 6 patients with Cohen syndrome shows that the clinical features are rather stable during evolution. Description of their actual behavior on the basis of standardized questionnaires shows that no severe behavior problems are observed in any of the 6 patients. Taking into account their mental age, their behavior is quiet and easy to handle by their environment.
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PMID:The long term evolution of 6 adult patients with Cohen syndrome and their behavioral characteristics. 1856 96

Microarray-based comparative genomic hybridization (array CGH) has revolutionized clinical cytogenetics, as it provides a relatively quick method to scan the genome for gains and losses of chromosomal material with significantly higher resolution and greater clinical yield than was previously possible. A number of different array CGH platforms have emerged and are being used successfully in the diagnostic setting. In the past few years, these new methodologies have led to the identification of novel genomic disorders in patients with developmental delay/mental retardation and/or multiple congenital anomalies (DD/MR/MCA) as well as the discovery that each individual carries inherited copy number variations (CNV) whose contributions to genetic variation and complex disease are not yet well understood. Although array CGH is currently being used as an adjunct test to standard karyotype analysis, it is likely to become the genetic test of choice, especially in cases of idiopathic MR/MCA.
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PMID:Clinical utility of array CGH for the detection of chromosomal imbalances associated with mental retardation and multiple congenital anomalies. 1915 22

First described in 1974, FG syndrome (FGS) is an X-linked multiple congenital anomaly/mental retardation (MCA/MR) disorder, characterized by high clinical variability and genetic heterogeneity. Five loci (FGS1-5) have so far been linked to this phenotype on the X chromosome, but only one gene, MED12, has been identified to date. Mutations in this gene account for a restricted number of FGS patients with a more distinctive phenotype, referred to as the Opitz-Kaveggia phenotype. We report here that a p.R28L (c.83G-->T) missense mutation in CASK causes FGS phenotype in an Italian family previously mapped to Xp11.4-p11.3 (FGS4). The identified missense mutation cosegregates with the phenotype in this family and is absent in 1000 control X chromosomes of the same ethnic origin. An extensive analysis of CASK protein functions as well as structural and dynamic studies performed by molecular dynamics (MD) simulation did not reveal significant alterations induced by the p.R28L substitution. However, we observed a partial skipping of the exon 2 of CASK, presumably a consequence of improper recognition of exonic splicing enhancers (ESEs) induced by the c.83G-->T transversion. CASK is a multidomain scaffold protein highly expressed in the central nervous system (CNS) with specific localization to the synapses, where it forms large signaling complexes regulating neurotransmission. We suggest that the observed phenotype is most likely a consequence of an altered CASK expression profile during embryogenesis, brain development, and differentiation.
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PMID:A missense mutation in CASK causes FG syndrome in an Italian family. 1920 May 22


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