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

We report on an aneuploidy syndrome due to the unbalanced segregation of a familial translocation (4;21)(p16.3;q22.1) causing a partial 4p monosomy and a partial 21q trisomy. The three affected children presented with severe failure to thrive, short stature, microcephaly, profound hypotonia, and mental retardation. The face, very similar in the three children, is characterized by frontal bossing, upslanting of the palpebral fissures, short nose, and deep set ears, giving the overall appearance of the Down syndrome. The molecular study has defined the aneuploid segment on both 4p and 21q. Most of the Down syndrome critical region was found to the trisomic, while only part of the candidate Wolf-Hirschhorn syndrome critical region was deleted, suggesting that this region is not critical for the major malformations characteristic for WHS.
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PMID:Molecular and cytogenetic characterization of a recurrent unbalanced translocation (4;21)(p16.3;q22.1): relevance to the Wolf-Hirschhorn and Down syndrome critical regions. 872 87

In 1990, Lambotte syndrome was reported as an apparently autosomal recessive multiple congenital anomaly/mental retardation (MCA/MR) syndrome observed in 4 of 12 sibs from a probably consanguineous mating [Verloes et al., Am J Med Genet 1990; 37:119-123]. Major manifestations included intrauterine growth retardation (IUGR), microcephaly, large soft pinnae, hypertelorism, beaked nose, and extremely severe neurologic impairment, with holoprosencephaly in one instance. After the observation of a further affected child born of one unaffected sister, in situ hybridization analysis and chromosome painting techniques demonstrated a subtle t(2;4)(q37.1; p16.2) translocation in the mother, suggesting a combination of 2q/4p trisomy/monosomy in all of the affected children of the family. Many private sporadic or recurrent MCA/MR syndromes maybe due to similar symmetric translocations, undetectable by conventional banding techniques.
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PMID:Private multiple congenital anomaly syndromes may result from unbalanced subtle translocations: t(2q;4p) explains the Lambotte syndrome. 940 61

We report on the prenatal diagnosis of two sib female fetuses with a satellited short arm of chromosome 4 and a male fetus with a satellited long arm of chromosome X. The first two fetuses had a cryptic balanced translocation (4;15)(p16;p11.1) inherited from a mother carrying a satellited 4p and having an affected child with the Wolf-Hirschhorn syndrome. The third fetus had a satellited Xq, with a deletion of subtelomeric region of Xq. The mother was subsequently found to have the same satellited Xq but without the presence of a reciprocal translocation. She decided to continue the pregnancy. The proband with a satellited Xq manifested developmental delay, mental retardation, hypertelorism, ptosis of one eye, low-set ears, and hearing disturbance at age 6 months. Fluorescence in situ hybridization (FISH) with a specific telomeric or subtelomeric probe, and genetic marker analyses were used to confirm the diagnosis. Pregnant women with satellited non-acrocentric chromosomes are at risk for carrying fetuses with chromosome abnormalities. If the X chromosome is involved, the fetuses can be affected with X-linked recessive disorders including mental retardation. Detailed genetic counselling, cytogenetic studies, FISH and genetic marker analyses are useful in prenatal detection of abnormal chromosome rearrangements.
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PMID:Prenatal diagnosis of inherited satellited non-acrocentric chromosomes. 1082 Apr 5

Interstitial deletion of the proximal short arm of chromosome 4, extending from p14 to p16.1 region, results in a distinct clinical syndrome. This proximal 4p deletion syndrome is characterized by variable degrees of mental retardation, unusual facies and minor dysmorphic features. Majority of the patients also show a tall, ectomorphic habitus and normal to excessive linear growth with age. While there have been several cases of such interstitial del(4p) cases reported, familial transmission of this condition has not been documented in the literature. This is the first report of a familial transmission of proximal del(4p) from a mother to her daughter, with both patients showing similar features. This report of the familial transmission of del(4p) has wider implications in genetic counseling.
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PMID:Familial interstitial deletion of chromosome 4 (p15.2p16.1). 1465 81

Finding the diagnosis in children with mental retardation and a normal karyotype, whether or not associated with dysmorphic features, is important for defining an eventual syndrome and for genetic counselling of the families. Telomeric re-arrangements may be a common and underestimated-to-date cause of non-syndromic mental retardation. Using a FISH-based approach combining subtelomeric probes, we report the detection of 4 cases of cryptic translocations t(2;10)(p25.3;q26.3), t(4;17)(p16.2;q25), t(4;20)(p16.2;q13) and t(5;7)(p15.3;q36) associated with MR and dysmorphic features. We discuss the usefulness of subtelomeric FISH in children with unexplained delayed psychomotor development, when the genetic cause remains unknown and the karyotype is normal.
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PMID:Six cases of cryptic subtelomeric translocations in four families: the use of subtelomeric FISH probes as a diagnostic tool. 1671 73

4p Monosomy and 12p trisomy have been discussed and redefined along with recently reviewed chromosomal syndromes. 12p Trisomy syndrome is characterized by normal or increased birth weight, developmental delay with early hypotonia, psychomotor delay, and typical facial appearance. Most likely, the observed phenotypic variability depends on the type and extent of the associated partial monosomy. Partial deletions of the short arm of one chromosome 4 cause the Wolf-Hirschhorn syndrome (WHS). Affected patients present Greek helmet face, growth and mental retardation, hypotonia, and seizures. The combination of these characteristics constitutes the phenotypic core of WHS. We present a clinical and molecular cytogenetic characterization of a 4-year old mentally retarded girl with macrosomy, facial dysmorphisms, and epilepsy, in whom an unbalanced t(4;12)(p16.3;p13.3) translocation was detected, giving rise to partial 4p monosomy and partial 12p trisomy. Because the patient shows most of the phenotypic characteristics of 12p trisomy, this case could contribute to a better definition of the duplicate critical region that determines the phenotype of the 12p trisomy syndrome.
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PMID:Trisomy 12p and monosomy 4p: phenotype-genotype correlation. 1937 4

Submicroscopic structural chromosomal aberrations (microduplications and microdeletions) are believed to be common causes of mental retardation. These so-called copy number variations can now be routinely detected using various platforms for array-based comparative genomic hybridization (array-CGH), which allow genome-wide identification of pathogenic genomic imbalances. In this study, oligonucleotide-based array-CGH was used to investigate a panel of 23 patients with mental retardation and developmental delay, dysmorphic features or congenital anomalies. Array-CGH confirmed or revealed 16 chromosomal aberrations in a total of 12 patients. Analysis of parental samples showed that five aberrations had occurred de novo: del(1)(p36.33p36.23), del(4)(p16.3p16.2) joined with dup(8)(p23.3p23.1), del(6)(q14.1q15), del(11)(q13.1q13.4). Three aberrations appeared to be inherited from an unaffected parent: dup(3)(q29), del(6)(q12), dup(16)(p13.11). Six aberrations appeared to be inherited from a parental carrier: del(1)(p36.33) joined with dup(12)(q24.32), del(21)(q22.2q22.3) joined with dup(11)(q24.2q25), del(X)(q22.3) and del(1)(q21.1). In two cases, parents were not available for testing: del(17)(q11.2q12) and del(2)(q24.3q31.1). Our results show that the use of oligonucleotide-based array- CGH in a clinical diagnostic laboratory increases the detection rate of pathogenic submicroscopic chromosomal aberrations in patients with mental retardation and congenital abnormalities, but it also presents challenges for clinical interpretation of the results (i.e., distinguishing between pathogenic and benign variants). Difficulties with analysis notwithstanding, the array-CGH is shown to be a sensitive, fast and reliable method for genome-wide screening of chromosomal aberrations in patients with mental retardation and congenital abnormalities.
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PMID:Analysis of chromosomal aberrations in patients with mental retardation using the array-CGH technique: a single Czech centre experience. 2212 63

Partial trisomy 3p results from either unbalanced translocation or de novo duplication. Common clinical features consist of dysmorphic facial features, congenital heart defects, psychomotor and mental retardation, abnormal muscle tone, and hypoplastic genitalia. In this paper, we report a case of partial trisomy 3p with rare clinical manifestations. A full-term, female newborn was transferred to our clinic. She had cleft lip-plate, dysgenesis of the corpus callosum, patent ductus arteriosus, pulmonary hypertension, and severe right-sided hydronephrosis, associated with ureteropelvic junction obstruction. Cytogenetic investigation revealed partial trisomy 3p; 46,XX,der(4)t(3;4) (p21.1;p16). The karyotype of her father showed a balanced translocation, t(3;4)(p21.1;p16). Therefore, the size of duplication can be an important factor.
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PMID:A case of partial trisomy 3p syndrome with rare clinical manifestations. 2247 66

We provide a detailed clinical and molecular analysis of 2 patients with de novo interstitial duplications at 2p14-p16.1 and 2p16.1-p22.1. The 10.13-Mb duplication of chromosome 2p14-p16.1 was identified in a 9-year-old boy with mental retardation, behavioral problems (hyperactivity, hyperphagia, and subsequent vomiting), recurrent respiratory tract infections, macrocephaly, epilepsy, and dysmorphic features. The 17.49-Mb duplication of 2p16.1-p22.1 was found in a 17-year-old girl with moderate mental retardation, behavioral and emotional problems, anxiety, and facial dysmorphic features. Very few cases of de novo interstitial duplication of 2p14-p22.1 are reported in the literature, with the great majority of them lacking a detailed molecular analysis. The abnormal phenotype of these cases is caused by mechanisms such as the overdose of a duplicated gene (or genes), the disruption of a gene or its regulatory sequence by the breakpoints of duplication, or by an excess of genetic material which may disorganize chromatin conformation affecting distant gene expression. The clinical and molecular analysis of these 2 rare de novo interstitial duplications provides useful information which is extremely valuable for clinical evaluation at the prenatal and postnatal level and for the molecular understanding of the underlying mechanisms of human diseases.
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PMID:Two new de novo interstitial duplications covering 2p14-p22.1: clinical and molecular analysis. 2303 92

Marker chromosomes are very rare in Klinefelter patients and phenotypic findings are related to the affected chromosomal region. The phenotypic effects of small supernumerary marker chromosomes (sSMC) range from multiple malformations/mental retardation to no effect (ie a normal phenotype). This wide spectrum of phenotypes is due to the origin, structure and gene content of the marker chromosome. The first Klinefelter case with sSMC 9 was published by Liehr et al in 2005. The present case was referred for chromosomal analysis because of dysmorphic features, speech delay and mild mental retardation. Conventional cytogenetic analysis revealed the 47XXY karyotype in 17 metaphases and the 48 XXY + marker karyotype in eight metaphases. Fluorescence in situ hybridization (FISH) analysis to identify the marker chromosome was performed using the LSI p16 (9p21) Spectrum Orange/CEP 9 SpectrumGreen Probe (Vysis CDKN2A/CEP 9 FISH Probe) and partial trisomy 9 mosaicism was confirmed in this patient. To our knowledge, this is the second case of Klinefelter syndrome with a small supernumerary marker chromosome derived from chromosome 9.
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PMID:Another small supernumerary marker chromosome derived from chromosome 9 in a Klinefelter patient. 2402 Feb 36


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