Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 1-year-old male infant was found to have a de novo unbalanced translocation, resulting in trisomy for a portion of the short arm of chromosome 3, i.e. 46,XY,der(7)t(3;7) (p24.1;p22). Previous cases with a so-called "trisomy 3p syndrome" were evaluated by GTG banding, while we attempted to characterize the present case by the FISH-technique. The major clinical features included: dysmorphic ears, decreased muscle tone and seizure episodes associated with fever, which are concordant with "trisomy 3p syndrome". The most common malformations of trisomy 3p syndrome are: psychomotor and mental retardation, short neck, hypertelorism/telecanthus and congenital heart defects. Predominantly, the 3p trisomies have been maternally derived and the major mechanism of inheritance is due to a malsegregation of the chromosomes that are involved in a parental balanced translocation. A review of 44 cases from 35 studies revealed that the clinical manifestations have been quite varied, depending upon the amount of 3p2 material in the trisomic state, but interestingly a recognizable pattern of features was obvious in those cases whose cytogenetic findings and clinical histories were known.
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PMID:Molecular characterization of trisomic segment 3p24.1-->3pter: a case with review of the literature. 758 45

We have identified a new mutation of Norrie disease (ND) gene in two Japanese males from unrelated families; they showed typical ocular features of ND but no mental retardation or hearing impairment. A mutation was found in both patients at the initiation codon of exon 2 of the ND gene (ATG to GTG), with otherwise normal nucleotide sequences. Their mothers had the normal and mutant types of the gene, which was expected for heterozygotes of the disease. The mutation of the initiation codon would cause the failure of ND gene expression or a defect in translation thereby truncating the amino terminus of ND protein. In view of the rarity and marked heterogeneity of mutations in the ND gene, the present apparently unrelated Japanese families who have lived in the same area for over two centuries presumably share the origin of the mutation.
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PMID:Novel mutation at the initiation codon in the Norrie disease gene in two Japanese families. 781 11

We report on a 4 year-old girl with a 1p36.3-pter deletion. Clinical findings included minor anomalies of face and distal limbs, patent ductus arteriosus, the Ebstein heart anomaly, and brain atrophy with seizures. Conventional GTG-banded chromosome analysis revealed a normal (46,XX) result. Subsequent analysis by fluorescent in situ hybridization (FISH) using distal probes demonstrated a deletion of 1p36.6-pter. Molecular investigations with microsatellite markers showed hemizygosity at three loci at 1p36.3 with loss of the paternal allele. The deletion of 1p36.3 is difficult to identify by banding alone; indeed, our patient represents the third reported case with a del(1)(p36.3) that was detected only after more detailed analysis. In all three cases the deletion was detected through screening of patients with multiple congenital anomalies/mental retardation syndromes suggestive of autosomal chromosome aberrations for subtelomeric submicroscopic deletions by means of FISH or microsatellite marker analysis. On the basis of these observations we highly recommend that FISH with a subtelomeric 1p probe be routinely performed in patients with similar facial phenotype, severe mental retardation and seizures, and a heart malformation, particularly the Ebstein anomaly.
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PMID:Terminal deletion, del(1)(p36.3), detected through screening for terminal deletions in patients with unclassified malformation syndromes. 1056 88

We present two brothers with mental retardation, seizures disorder, generalized muscular hypertonia, kyphoscoliosis, minor anomalies and a prominent midface. GTG-banded chromosome analysis showed a derivative chromosome 14 without clues toward the origin of the rearrangement. Microdissection of the derivative chromosome 14 and subsequent reverse painting demonstrated partial trisomy 7q32-q34 as the unbalanced product of a maternal insertion (14;7). Thus, we identified two cases with pure trisomy 7q32-q34 that allowed further delineation of this aneusomy syndrome.
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PMID:Mental and psychomotoric retardation in two brothers with pure partial trisomy 7q32-q34 due to a maternal insertion (14;7). 1076 86

The etiology of mental retardation (MR), often presenting as developmental delay in childhood, is unknown in approximately one-half of cases. G-banding is the standard method for investigating those suspected of having a chromosomal etiology; however, detection of structural abnormalities is limited by the size and pattern of the G-bands involved. Rearrangements involving subtelomeric regions have been shown to cause MR and this has generated interest in investigating the prevalence of these rearrangements using telomere-specific probes. In addition, because cryptic interchromosomal rearrangements may not be small or confined to chromosomal ends, spectral karyotyping (SKY) using chromosome-specific painting probes may be of value. We report here a study using these two FISH-based techniques in 50 children with idiopathic MR or developmental delay and normal GTG-banded karyotypes. Our objective was to assess the prevalence of cryptic rearrangements in this population using subtelomeric FISH and SKY. Three rearrangements were detected by subtelomeric FISH: a derivative 5 from a maternal t(5;21); a recombinant 11 from a paternal pericentric inversion; and a 2q deletion that was also present in the mother. Only the derivative 5 was detected by SKY. SKY did not detect any interstitial interchromosomal rearrangement. The prevalence of clinically significant cryptic rearrangements by subtelomeric FISH and SKY was thus 4% (95% confidence interval 0.5-13.7) and 2% (95% CI 0.05-10.7), respectively. This study supports the view that G-banding does not detect all clinically significant chromosomal abnormalities and that subtelomeric FISH and SKY can detect some of these abnormalities.
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PMID:Detecting rearrangements in children using subtelomeric FISH and SKY. 1184 Apr 82

A girl with psychomotor retardation and a pattern of minor anomalies was found to have a slightly enlarged short arm of chromosome 18 by conventional GTG-banded chromosome examination. The 18p+chromosome has also been found in the father. FISH studies using chromosome 18-and chromosome 20-specific painting probes confirmed a reciprocal whole arm translocation between chromosomes 18 and 20 in the father, resulting in monosomy of the short arm of chromosome 18 and trisomy of the short arm chromosome 20 in the patient. FISH analysis using a chromosome 18 alpha-satellite-specific probe showed a reduced signal intensity. The patient presented with a flat, oval face, upslanting palpebral fissures, periorbital fullness, and mental retardation; she also had chronic diarrhea with milk protein intolerance and juvenile rheumatoid arthritis at age 5 years. Juvenile rheumatoid arthritis, like several other immunologic disorders, has occasionally been reported in patients with deletion of 18p, and thus most likely loss of a gene or genes on 18p is responsible for various immunologic disorders occurring in these patients.
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PMID:Patient with rheumatoid arthritis and MCA/MR syndrome due to unbalanced der(18) transmission of a paternal translocation t(18;20)(p11.1;p11.1). 1189 91

Recent studies have shown that cryptic unbalanced subtelomeric rearrangements contribute to a significant proportion of idiopathic syndromic mental retardation cases. Using a fluorescent genotyping based strategy, we found a 10% rate of cryptic subtelomeric rearrangements in a large series of 150 probands with severe idiopathic syndromic mental retardation and normal RHG-GTG banded karyotype. Fourteen children were found to carry deletions or duplications of one or more chromosome telomeres and two children had uniparental disomy. This study clearly shows that fluorescent genotyping is a sensitive and cost effective method that not only detects cryptic subtelomeric rearrangements but also provides a unique opportunity to detect uniparental disomies. We suggest giving consideration to systematic examination of subtelomeric regions in the diagnostic work up of patients with unexplained syndromic mental retardation.
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PMID:Automated fluorescent genotyping detects 10% of cryptic subtelomeric rearrangements in idiopathic syndromic mental retardation. 1195 Aug 56

Poly-Y karyotypes, except for 47,XYY, are rare events in humans. For instance, Y chromosome tetrasomy has been reported 10 times, 2 of which were by structural rearrangement. We present a 2-year-and-4-month-old boy who was referred for cytogenetic assessment because of global psychomotor delay. The GTG- and CBG-banded karyotypes on PHA-stimulated lymphocytes showed two cell populations, one of them contained two identical isodicentric Y chromosomes, which was seen in 93% of metaphases analyzed, and a 45,X cell line (7%). This was confirmed by FISH with probes DYZ3 (recognizing the centromeric region of the Y chromosome), 91H4.5 (recognizing Yp11.2), and DYZ1 (recognizing Y heterochromatin in Yq12). The breakpoint has occurred near the telomeric end of the heterochromatic region. Therefore, the karyotype is mos 47,X,idic(Y)(q12)x2[123]/45,X[9]. This is the second time that such a karyotype has been reported. This chromosomal anomaly was formed most likely by a U-type exchange. Clinical features included speech delay, short stature, brachycephaly, large ears, bilateral epicanthal folds, hypertelorism, delayed teeth eruption, bilateral radio-ulnar synostosis, bilateral fifth finger clinodactyly, normal external genitalia, and impulsive behavior. The father had normal phenotype and karyotype. A review of the tetrasomy Y patients is presented. All patients with Y chromosome tetrasomy exhibit some degree of mental retardation, various skeletal abnormalities, and facial dysmorphism. Nevertheless, the correlation between karyotype and phenotype is not yet well defined since few cases have been reported. This clinical report will be helpful in defining the phenotypic range associated with tetrasomy Y.
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PMID:Tetrasomy Y by structural rearrangement: clinical report. 1221 Feb 99

We report on the fourth known case with an interstitial deletion in 15q21. In the present case the breakpoints have been determined by GTG-banding, microdissection and the recently developed multicolor banding (MCB) technique as 15q21.1-q21.3. Common features in all four cases are mental retardation, growth retardation, a beak-like nose with hypoplastic alae nasi and a thin upper lip. Additional frequent features are small hands and feet, hypotonia, low hair implantation, low set ears, clinodactyly and obesity. The possibility that a critical region for a new microdeletion-syndrome is situated in 15q21 is discussed.
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PMID:Evidence for a new microdeletion syndrome in 15q21. 1268 92

We describe a 4-year-old boy with an accessory right thumb, short and broad toes, cryptorchidism, micrognathia, abnormally modeled ears, and delayed speech development. The chromosome analysis of patient's peripheral blood lymphocytes by conventional GTG banding demonstrated a small deletion in the long arm of chromosome 1. Confirmation and defined localization of the deleted segment to chromosomal bands 1q25.3-q31.3 was obtained by high resolution prometaphase analysis. Molecular studies, using a set of polymorphic chromosome 1q specific microsatellite markers, localized the deletion between the markers D1S2127 and D1S1727 on the paternally inherited chromosome 1. The maximum physical distance between these markers is approximately 21 Mb. The previously described two patients with 1q25-q31 deletions both had severe clinical manifestations, just as the other 10 patients with the proposed "intermediate 1q deletion syndrome," associated with 1q25-q32 deletions. Distinct from all these patients, the clinical picture of our patient is markedly milder, i.e., without growth retardation, microcephaly, or clear mental retardation.
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PMID:Interstitial 1q25.3-q31.3 deletion in a boy with mild manifestations. 1460 52


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