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

Eight patients (three sporadic, five from two families) with the velo-cardio-facial syndrome (VCFS) or Shprintzen syndrome are reported. Major clinical findings of this syndrome include a characteristic pattern of facial dysmorphisms, cleft palate, cardio-vascular malformations, and (mostly mild-to-moderate) mental retardation or learning difficulties. The syndrome probably is caused by a dominant gene with very variable expression. From previous reports mostly ascertained from cardio-vascular or cleft palate clinics, the incidence of cleft palate and heart defects was calculated to be 98% and 82%, respectively. Out of eight patients of this study who were diagnosed mainly through their pattern of facial dysmorphisms, only two and four had clefts and heart defects, respectively, further demonstrating the variability in the expression of this gene. Similarly, mental retardation, noted in 100% of previous publications, was not present in all of our patients. In two instances, examination of the mother revealed that she probably carried the mutant gene, but that she showed a milder clinical expression than the index patient. It is suggested that careful family investigations should be performed following detection of an index patient, and that the rate of fresh mutations might be not as high as previously assumed.
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PMID:The velo-cardio-facial (Shprintzen) syndrome. Clinical variability in eight patients. 381 57

The smallest region of deletion overlap in the patients we have studied defines a DIGeorge syndrome/velocardiofacial syndrome (DGS/VCFS) minimal critical region (MDGCR) of approximately 250 kb within 22q11. A de novo constitutional balanced translocation has been identified within the MDGCR. The patient has some features which have been reported in individuals with DGS/VCFS, including: facial dysmorphia, mental retardation, long slender digits and genital anomalies. We have cloned the breakpoint of his translocation and shown that it interrupts the clathrin heavy chain-like gene (CLTCL) within the MDGCR. The breakpoint of the translocation partner is in a repeated region telomeric to the rDNA cluster on chromosome 21p. Therefore, it is unlikely that the patient's findings are caused by interruption of sequences on 21p. The chromosome 22 breakpoint disrupts the 3' coding region of the CLTCL gene and leads to a truncated transcript, strongly suggesting a role for this gene in the features found in this patient. Further, the patient's partial DGS/VCFS phenotype suggests that additional features of DGS/VCFS may be attributed to other genes in the MDGCR. Thus, haploinsufficiency for more than one gene in the MDGCR may be etiologic for DGS/VCFS.
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PMID:Disruption of the clathrin heavy chain-like gene (CLTCL) associated with features of DGS/VCFS: a balanced (21;22)(p12;q11) translocation. 914 38

We report data on a group of 37 VCFS patients with specific reference to their intelligence, behaviour, and social competence. Fifty five percent of the children had a borderline to normal IQ. Mental retardation (defined as IQ < 70 or > -2 SD below the mean) was found in 45%. In the majority, the mental retardation was mild (38%) and only two patients had moderate mental retardation. Severe mental retardation seems to be rare in VCFS. The present study shows also that the incidence of mental retardation is much higher in the familial than the de novo group. Intelligence is not correlated with the presence or absence of a heart defect. Significantly higher verbal IQs than performance IQs (probably related to deficits in visuospatial-perceptual functioning) were found. Problems in social-emotional functioning and attention were also found. Further longitudinal studies are necessary to provide an accurate prognosis and appropriate intervention for VCFS children.
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PMID:Intelligence and psychosocial adjustment in velocardiofacial syndrome: a study of 37 children and adolescents with VCFS. 919 63

We have identified six children with a distinctive facial phenotype in association with mental retardation (MR), microcephaly, and short stature, four of whom presented with Hirschsprung (HSCR) disease in the neonatal period. HSCR was diagnosed in a further child at the age of 3 years after investigation for severe chronic constipation and another child, identified as sharing the same facial phenotype, had chronic constipation, but did not have HSCR. One of our patients has an interstitial deletion of chromosome 2, del(2)(q21q23). These children strongly resemble the patient reported by Lurie et al with HSCR and dysmorphic features associated with del(2)(q22q23). All patients have been isolated cases, suggesting a contiguous gene syndrome or a dominant single gene disorder involving a locus for HSCR located at 2q22-q23. Review of published reports suggests that there is significant phenotypic and genetic heterogeneity within the group of patients with HSCR, MR, and microcephaly. In particular, our patients appear to have a separate disorder from Goldberg-Shprintzen syndrome, for which autosomal recessive inheritance has been proposed because of sib recurrence and consanguinity in some families.
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PMID:Hirschsprung disease, microcephaly, mental retardation, and characteristic facial features: delineation of a new syndrome and identification of a locus at chromosome 2q22-q23. 1292 73

Velo-cardio-facial syndrome (VCFS) is caused by a microdeletion in the long arm of chromosome 22 and is associated with an increased frequency of schizophrenia and bipolar mood disorder. The purpose of this study was to investigate the genetic, physical, developmental and psychiatric features of schizophrenic patients with VCFS microdeletion. It describes the clinical findings in four schizophrenic inpatients with the characteristic chromosomal deletion. The four patients displayed delayed motor development, language deficits, learning disabilities, mental retardation, early age of onset, chronic and disabling course of illness and poor response to classical neuroleptic drugs and electroconvulsive therapy. Two patients benefited from treatment with clozapine. We suggest that schizophrenic patients with a history of delayed motor development, early onset of the disorder, history of learning disability, mental retardation, congenital cardiac anomalies and/or hypernasal speech should be screened for the velo-cardio-facial syndrome deletion. The implications of this study for psychiatric phenotype, nosology, disease mechanism, and possible new treatments in the future are discussed.
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PMID:Clinical characteristics of schizophrenia associated with velo-cardio-facial syndrome. 998 47

The evaluation of mental retardation is always a challenge to clinicians. The recognition of specific physical or behavioral characteristics can vastly improve diagnostic yield. Several genetic disorders have been identified to have certain behavioral characteristics, such as Williams syndrome, Smith-Magenis syndrome, and the velocardiofacial syndrome (VCFS). The deletion affecting the chromosome 22q in the most distal band (22q13) appears to define yet another neurobehavioral phenotype. In addition to our report, there are about 17 other cases published of this particular deletion syndrome. We describe three children who share features of developmental delay and pervasive behaviors in addition to normal to advanced growth patterns. Results of cytogenetic analysis suggest that the 3 patients share a deletion affecting the terminal 22q13 region. Two were found to have a cryptic deletion, in the third it was detected by conventional cytogenetics. The cryptic deletions were demonstrated using fluorescent in situ hybridization (FISH), where the control probe for the DiGeorge/VCFS region was deleted. While there remain gaps in our understanding of this particular deletion syndrome, we propose that patients with normal or advanced growth, significantly delayed speech, deviant development and pervasive behaviors, with minor facial dysmorphism, be screened for this deletion.
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PMID:Genetic evaluation of pervasive developmental disorders: the terminal 22q13 deletion syndrome may represent a recognizable phenotype. 1073 30

Patients with a deletion of chromosome band 22q11 are described as having DiGeorges syndrome, velocardiofacial syndrome or chromosome 22q11 deletion syndrome depending on clinical manifestations. The patients have variable severity and combinations of conotruncal heart defects, abnormalities of the ear and palate, facial dysmorphism and mental retardation as well as partial or complete aplasia/hypoplasia of the thymus and endocrine dysfunction, e.g. hypoparathyroidism. The patients may present with impaired immune function, heart failure, hypocalcaemia, facial dysmorphism, impaired hearing and mental retardation. The syndrome, which is a significant cause of heart and craniofacial defects as well as mental retardation, is probably underdiagnosed. In each of the above mentioned phenotypical presentations, chromosome 22q11 deletion syndrome should be considered.
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PMID:[DiGeorge syndrome. Velocardiofacial syndrome/chromosome 22q11 deletion syndrome]. 1082 40

Hirschsprung disease, mental retardation, microcephaly, and specific craniofacial dysmorphism were observed in three children from a large, consanguineous, Moroccan family. A fourth child showed similar clinical features, with the exception of Hirschsprung disease. The association of these abnormalities in these children represents the Goldberg-Shprintzen syndrome (OMIM 235730). Mutation scanning of genes potentially involved in Hirschsprung disease, RET, GDNF, EDN3, and EDNRB, showed a sequence variant, Ser305Asn, in exon 4 of the EDNRB gene in the index patient of this family. The Ser305Asn substitution present in two of the four patients and four healthy relatives and absent in one of the remaining two patients illustrates the difficulties in interpreting the presence of mutations in families with Hirschsprung disease. It is unlikely that the EDNRB variant contributes to the phenotype. This consanguineous family might be useful for the identification of a Goldberg-Shprintzen locus.
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PMID:A consanguineous family with Hirschsprung disease, microcephaly, and mental retardation (Goldberg-Shprintzen syndrome). 1087 40

The 22q11 region is involved in chromosomal rearrangements that lead to altered gene dosage, resulting in genomic disorders that are characterized by mental retardation and/or congenital malformations. Three such disorders-cat-eye syndrome (CES), der(22) syndrome, and velocardiofacial syndrome/DiGeorge syndrome (VCFS/DGS)-are associated with four, three, and one dose, respectively, of parts of 22q11. The critical region for CES lies centromeric to the deletion region of VCFS/DGS, although, in some cases, the extra material in CES extends across the VCFS/DGS region. The der(22) syndrome region overlaps both the CES region and the VCFS/DGS region. Molecular approaches have revealed a set of common chromosome breakpoints that are shared between the three disorders, implicating specific mechanisms that cause these rearrangements. Most VCFS/DGS and CES rearrangements are likely to occur by homologous recombination events between blocks of low-copy repeats (e.g., LCR22), whereas nonhomologous recombination mechanisms lead to the constitutional t(11;22) translocation. Meiotic nondisjunction events in carriers of the t(11;22) translocation can then lead to offspring with der(22) syndrome. The molecular basis of the clinical phenotype of these genomic disorders has also begun to be addressed. Analysis of both the genomic sequence for the 22q11 interval and the orthologous regions in the mouse has identified >24 genes that are shared between VCFS/DGS and der(22) syndrome and has identified 14 putative genes that are shared between CES and der(22) syndrome. The ability to manipulate the mouse genome aids in the identification of candidate genes in these three syndromes. Research on genomic disorders on 22q11 will continue to expand our knowledge of the mechanisms of chromosomal rearrangements and the molecular basis of their phenotypic consequences.
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PMID:Genomic disorders on 22q11. 1192 70

New high-resolution cytogenetical technique identified an increased number of terminal, interstitial and subtelomeric microdeletion as the etiology of many syndromes of multiple congenital anomalies, mental retardation and facial dysmorphy. A loss of contiguous genes shows a high phenotypical variability and at the same time it is significant for genetic prognosis. 1) Variability of clinical features depends on the size and pathogenetic mechanism of underlying deletion; 2) Dysmorphic face features are of a characteristic type and can be somatoscopically recognized; 3) Heart defects and mental retardation are common features of microdeletion syndromes; 4) New mutations represent the most common etiology of microdeletions; only 1 to 10% of mutations are transmitted from the parental gonadal mosaics, from the balanced translocation or from the same microdeletion in parents; 5) Recurrence risk is low, but it may be as high as 50% in individual cases of inherited mutation; 6) Genetic heterogeneity is high and the responsible genes can be located at different chromosomes (e.g. Di George syndrome due to mutation on 22q or 10q) and can also result from microdeletion or point mutation (in the Shprintzen syndrome 70% represent microdeletion and 30% point mutation at 22q11, in Rubinstein-Taybi syndrome 10% cases result from microdeletions and 90% from point mutations); 7) Population incidence of microdeletions is high (1:4000 to 1:30,000) because their etiologic mechanism is related to the common unequal crossing over; 8) Imprinting plays a role in some cases, e.g. Prader-Willi syndrome results from nullisomy of paternal 15q12 chromosome, Angelman syndrome is related to that of maternal 15q12 chromosome; 9) Prenatal prevention of the high risk familial chromosomal rearrangements is feasible since the 12th gestation week.
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PMID:[Microdeletion syndromes]. 1223 21


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