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

We studied the abnormal ocular and systemic findings in one case of true triploidy and two cases of triploid mosaicism. A liveborn triploid child 69,XXY, had abnormalities including cebocephaly, a single midline nostril, incomplete cleft palate, transverse palmar creases, partial syndactyly, and ambiguous genitalia. Ocular abnormalities included hypotelorism, blepharophimosis, microcornia, iris coloboma, cataract, persistent hyaloid vasculature, retinal dysplasia, and optic atrophy. A 16-year-old girl with triploid mosaicism had congenital left facial and body hemiatrophy, both growth and mental retardation, left-sided grand mal seizures, incontinentia pigmenti of both legs, partial syndactyly, and generalized weakness. Results of her ocular examination were within normal limits. A 13-year-old boy with triploid mosaicism exhibited both growth and mental retardation, truncal obesity, and required a brace to support his back. Ocular findings included synophrys, bilateral blepharoptosis, and abnormal results of Schirmer tear test. Studies indicate a wide spectrum of ocular and systemic abnormalities occur that are presumably associated with the chromosome error.
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PMID:Ocular findings in triploidy. 41 37

Genetic, and indeed genomic, imprinting does occur in humans. This is manifest at the level of the genome, the individual chromosome, subchromosomal region or fragile site, or the single locus. The best evidence at the single gene level comes from a consideration of familial tumour syndromes. Chromosomal imprinting effects are revealed when uniparental disomy occurs, as in the Prader-Willi syndrome and doubtless other sporadic, congenital anomaly syndromes. Genomic imprinting is manifest in the developmental defects of hydatidiform mole, teratoma and triploidy. Fragile (X) mental retardation shows an unusual pattern of inheritance, and imprinting can account for these effects. Future work in clinical genetics may identify congenital anomalies and growth disorders caused by imprinting: the identification of imprinting effects for specific chromosomal regions in mice will allow the examination of the homologous chromosomal region in humans.
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PMID:Genetic imprinting in clinical genetics. 215 Oct 33

We report on a four year old boy with multiple congenital anomalies and mental retardation due to incomplete triploidy (diploid triploid mixoploidy). Initially, we had thought of the Silver-Russell syndrome. The main characteristics in the patient are short stature, body asymmetry, hypogenitalism, and considerable mental retardation. In addition, there are several minor anomalies of the hands and feet. The diagnosis was verified by microscopic detection of a triploid cell line in cultivated skin fibroblasts and by supplementary studies using flow cytometry. The characteristics of this recognizable multiple congenital anomalies/mental retardation syndrome are discussed with reference to the pertinent literature. As differential diagnosis, in particular the Silver-Russell syndrome has to be taken into account.
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PMID:[Abnormalities-retardation syndrome caused by incomplete triploidy]. 338 50

Prenatal karyotyping using stimulated fetal blood lymphocytes was undertaken in 170 pregnancies between 16 and 36 weeks gestation for the following reasons--mosaicism or marker chromosomes found in amniotic fluid culture; a family history of X-linked mental retardation with fragile Xq28; fetal abnormalities detected ultrasonographically; late booking or amniotic fluid culture failure in patients with advanced age or balanced translocations; and twin pregnancies discordant for a chromosomal anomaly. Forty-one karyotypic abnormalities were detected (24%). These were: 45,X (7 cases), trisomy 13 (5 cases), trisomy 18 (6 cases), trisomy 21 (4 cases), twin pregnancy where one twin had trisomy 21 (1 case), supernumerary marker chromosome (3 cases, one of which occurred in a twin pregnancy), triploidy (3 cases), X-linked mental retardation with fragile site at Xq28 in males (6 cases), fetal erythroleukaemia (3 cases including 2 cases with Turner's), Fanconi's anaemia (1 case), unbalanced chromosome translocation 47,XY+der22,t(11;22) mat (1 case), mos 46,XX18p-/46,XX,-18+i(18q) (1 case), 46,XXdel(2q) (1 case), and 46,XYt(5;17) de novo (1 case). In fetuses at high risk of a chromosome aberration, a rapidly obtained karyotype is helpful and fetoscopy and fetal blood sampling are justified in the second or third trimester.
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PMID:Fetal blood chromosome analysis: some new indications for prenatal karyotyping. 404 97

Anomalies of chromosome number and structure are considered to be the most frequent cause of unexplained, non-syndromic developmental delay and mental retardation (DD/MR). High-resolution, genome-wide, array-based segmental aneusomy profiling has emerged as a highly sensitive technique for detecting pathogenic genomic imbalances. A review of 29 array-based studies of DD/MR patients showed that a yield of at least approximately 19% pathogenic aberrations is attainable in unselected, consecutive DD/MR referrals if array platforms with 30-70 kb median probe spacing are used as an initial genetic testing method. This corresponds to roughly twice the rate of classical cytogenetics. This raises the question whether chromosome banding studies, combined with targeted approaches, such as fluorescence in situ hybridisation for the detection of microdeletions, still hold substantial relevance for the clinical investigation of these patients. To address this question, we reviewed the outcome of cytogenetic studies in all 36,325 DD/MR referrals in the Netherlands during the period 1996-2005, a period before the advent of array-based genome investigation. We estimate that in a minimum of 0.78% of all referrals a balanced chromosomal rearrangement would have remained undetected by array-based investigation. These include familial rearrangements (0.48% of all referrals), de novo reciprocal translocations and inversions (0.23% of all referrals), de novo Robertsonian translocations (0.04% of all referrals), and 69,XXX triploidy (0.03% of all referrals). We conclude that karyotyping, following an initial array-based investigation, would give only a limited increase in the number of pathogenic abnormalities, i.e. 0.23% of all referrals with a de novo, apparently balanced, reciprocal translocation or inversion (assuming that all of these are pathogenic), and 0.03% of all referrals with 69,XXX triploidy. We propose that, because of its high diagnostic yield, high-resolution array-based genome investigation should be the first investigation performed in cases of DD/MR, detecting >99% of all pathogenic abnormalities. Performing both array investigation and karyotyping may not be a feasible option when laboratories are faced with a need to limit the number of genetic tests available for each patient. However, laboratories that supplant karyotyping by array-based investigation should be aware that, as shown here, a chromosomal abnormality, with possible pathogenic consequences for the patient or the family, will escape detection in about 0.78% of all DD/MR referrals.
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PMID:Array analysis and karyotyping: workflow consequences based on a retrospective study of 36,325 patients with idiopathic developmental delay in the Netherlands. 1936 74