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)

The clinical phenotype of patients with ring chromosome 22 includes mental retardation with severe language impairment, hypotonia, and dysmorphic facial features. In recent years an increasing number of patients with microscopic as well as cryptic terminal deletion involving band 22q13 have been described and their phenotype shows clinical features overlapping with patients with ring chromosome 22. Loss of DNA in the 22q13.3 region may lead to a clinically recognizable syndrome named "22q13.3 deletion syndrome." We report a patient with a ring chromosome 22 who has hypotonia, profound mental retardation, language impairment, dysmorphic features, and behavioral disorders. To check if the critical region responsible for "22q13.3 deletion syndrome" was absent in this ring, a fluorescent in situ hybridization (FISH) analysis using a probe corresponding to the ARSA locus was performed. In our patient, only one ARSA signal could be detected, indicating that the deletion encompassed the critical 22q13.3 region. A more detailed analysis of the deletion extent then was performed using a panel of fluorescent probes located within 22q13. These experiments allowed the identification of the breakpoint between CTA-299D3 and RP5-925J7 probe, located in 22q13.32. Deletion extent could be estimated to be about 2.5 Mb, and this larger deletion may explain the severity of clinical features observed in our patient.
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PMID:Characterization of the phenotype and definition of the deletion in a new patient with ring chromosome 22. 1537 17

We present a girl with a terminal 22q duplication due to an unbalanced chromosomal translocation: 46, XX, der(22)(qter --> q13.31::p11 --> qter). She presented with mild to moderate mental retardation, autism spectrum disorder, microcephaly and mild dysmorphic facial features. Because of nasal speech and mental retardation, FISH analysis for the DiGeorge/VCFS region was performed. In this analysis, an extra signal for the control probe LSI ARSA (22q13) on the short arm of one of the chromosomes 22 revealed the terminal duplication 22qter. The duplication was confirmed by means of 1Mb array-CGH and further delineated as a 5.5 Mb region: 46, XX, dup(22)(q13.31qter)(CTA-268H5 --> CTB-99K24)x3. Important phenotypic variability has been described among patients with terminal 22q duplications. However, by considering the present patient and a careful selection of literature reports describing pure trisomy 22qter and comparably small duplicated regions 22q13.3 to qter, we find evidence for a consistent clinical presentation: mild to moderate mental retardation, microcephaly and similar mild dysmorphic features. Furthermore we conclude that small terminal duplications of chromosome 22q may be more common than generally assumed but may remain undetected by high resolution karyotyping. The application of array-CGH in patients with mental retardation and only very mild dysmorphism may allow to detect small 22qter duplications more frequently.
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PMID:A cryptic duplication 22q13.31 to qter leads to a distinct phenotype with mental retardation, microcephaly and mild facial dysmorphism. 1923 79