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)

Seroconversion to cytomegalovirus occurs in 1-4% of pregnant women, most of whom are seropositive prior to pregnancy. In 0.2-2.5% of their newborn infants there is evidence of intrauterine infection; most are born without any clinical findings The typical clinical symptoms of symptomatic congenital CMV are observed in 10-20% of infected neonates. They include intrauterine growth restriction, microcephaly, hepatosplenomegaly, petechiae, jaundice, thrombocytopenia, anemia, chorioretinitis, hearing loss and/or other findings. Long-term neurodevelopmental sequelae include mental retardation, motor impairment, sensorineural hearing loss and/or visual impairment. These may occur even in infants who are free of symptoms at birth. Most infants born with severe neonatal symptoms of congenital CMV are born to mothers with primary infection during pregnancy. However, since about half of the infants infected with CMV in utero, including those with severe neonatal symptoms, are born to mothers with preconceptional immunity, we have to conclude that congenital CMV may be a significant problem even in children born to mothers with pre-pregnancy immunization. This may justify the use of invasive methods for the detection of possible fetal infection even in cases of non-primary CMV infection. This should also be a consideration when deciding upon population screening or immunization for CMV.
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PMID:Fetal effects of primary and non-primary cytomegalovirus infection in pregnancy: are we close to prevention? 1759 85

Monosomy 1p36 is the most common terminal deletion syndrome with an estimated occurrence of 1:5000 live births. Typically, the deletions span <10 Mb of 1pter-1p36.23 and result in mental retardation, developmental delay, sensorineural hearing loss, seizures, cardiomyopathy and cardiovascular malformations, and distinct facies including large anterior fontanel, deep-set eyes, straight eyebrows, flat nasal bridge, asymmetric ears, and pointed chin. We report five patients with 'atypical' proximal interstitial deletions from 1p36.23-1p36.11 using array-comparative genomic hybridization. Four patients carry large overlapping deletions of approximately 9.38-14.69 Mb in size, and one patient carries a small 2.97 Mb deletion. Interestingly, these patients manifest many clinical characteristics that are different from those seen in 'classical' monosomy 1p36 syndrome. The clinical presentation in our patients included: pre- and post-natal growth deficiency (mostly post-natal), feeding difficulties, seizures, developmental delay, cardiovascular malformations, microcephaly, limb anomalies, and dysmorphic features including frontal and parietal bossing, abnormally shaped and posteriorly rotated ears, hypertelorism, arched eyebrows, and prominent and broad nose. Most children also displayed hirsutism. Based on the analysis of the clinical and molecular data from our patients and those reported in the literature, we suggest that this chromosomal abnormality may constitute yet another deletion syndrome distinct from the classical distal 1p36 deletion syndrome.
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PMID:Identification of proximal 1p36 deletions using array-CGH: a possible new syndrome. 1785 Jun 29

An apparently new syndrome of congenital cataracts, sensorineural deafness, Down syndrome-like facial appearance, short stature, and mental retardation was described by Gripp et al. 1996. The authors reported on two unrelated patients with congenital cataracts, sensorineural deafness, distinctive facial appearance, mental retardation, postnatal short stature, and skeletal changes. We report on two additional patients with findings most similar to the reported patients by Gripp et al. 1996, including bilateral congenital cataracts, hearing loss, craniofacial abnormalities, short stature, skeletal abnormalities, and developmental delay. Both of the patients reported herein had chromosome microarray analysis, which showed normal results in Patient 2 but abnormal results in Patient 1 and his mother who both had a chromosome 11q25 subtelomere deletion. Patient 1 and his mother's findings are atypical for the common findings reported in Jacobsen syndrome (11q terminal deletion syndrome), and consistent with the patients reported by Gripp et al. 1996. The etiology for these cases has been unknown. The microarray results on Patient 1 suggest that the other patients with findings of developmental delay, short stature, congenital cataracts, sensorineural hearing loss, and similar craniofacial features may have either a microdeletion of chromosome 11q terminal region or haploinsufficiency of a gene localized to this region.
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PMID:Syndrome of congenital cataracts, sensorineural deafness, Down syndrome-like facial appearance, short stature, and mental retardation: two additional cases. 1793 51

X-linked syndromes associated with developmental delay and sensorineural hearing loss (SNHL) have been characterized at the molecular level, including Mohr-Tranebjaerg syndrome and Norrie disease. In this study we report on a novel X-linked recessive, congenital syndrome in a family with developmental delay and SNHL that maps to a locus associated with mental retardation (MR) for which no causative gene has been identified. The X-linked recessive inheritance and congenital nature of the syndrome was confirmed by detailed clinical investigation and the family history. Linkage mapping of the X-chromosome was conducted to ascertain the disease locus and candidate genes were screened by direct sequencing and STRP analysis. The recessive syndrome was mapped to Xp11.3-q21.32 and a deletion was identified in a regulatory region upstream of the POU3F4 gene in affected family members. Since mutations in POU3F4 cause deafness at the DFN3 locus, the deletion is the likely cause of the SNHL in this family. The choroideremia (CHM) gene was also screened and a novel missense change was identified. The alteration changes the serine residue at position 89 in the Rab escort 1 protein (REP-1) to a cysteine (S89C). Prenylation of Rab proteins was investigated in patients and the location of REP-1 expression in the brain determined. However, subsequent analysis revealed that this change in CHM was polymorphic having no effect on REP-1 function. Although the causative gene at the MR locus in this family has not been identified, there are a number of genes involved in syndromic and nonsyndromic forms of MR that are potential candidates.
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PMID:Molecular characterization of a novel X-linked syndrome involving developmental delay and deafness. 1793 54

DOOR syndrome (deafness, onychodystrophy, osteodystrophy, and mental retardation) is a rarely described disorder with less than 35 reports in the literature. The hallmarks of the syndrome, represented in the DOOR acronym, include sensorineural hearing loss, hypoplastic or absent nails on the hands and feet, small or absent distal phalanges of the hands and feet, and mental retardation. The purpose of our communication is to report on an additional patient with DOOR syndrome, delineate common as well as less frequent manifestations of DOOR syndrome, bring attention to the under appreciated facial features in DOOR syndrome, document the natural history of this disorder, and propose a suggested workup of those suspected of DOOR syndrome. DOOR syndrome is associated with characteristic, coarse facial features with large nose with wide nasal bridge, bulbous tip and anteverted nares, a long prominent philtrum and downturned corners of the mouth. The natural history is one of a deteriorative course, with progressive neurological manifestations including sensorineural deafness, seizures from infancy, optic atrophy, and a peripheral polyneuropathy. The majority of patients with DOOR syndrome have elevated levels of 2-oxoglutarate in the urine and plasma. In this report, we present a newborn with manifestations consistent with DOOR syndrome and a progressive clinical course. A comprehensive literature review reveals 32 patients with DOOR syndrome. In conclusion, DOOR syndrome is a neurometabolic disorder with recognizable facial features and a progressive natural history.
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PMID:DOOR syndrome: clinical report, literature review and discussion of natural history. 1799 65

Human Cytomegalovirus (CMV) is the main cause of mental retardation and sensorineural hearing loss related to congenital infections. Justification of systematic screening for fetal CMV infection is still controversial and is not recommended in most developed countries. This is mainly justified by the paucity of antenatal prognostic factors and the lack of established intrauterine treatment when fetal infection has been diagnosed. Our aim was to review the current state of the knowledge about the CMV congenital infection and to highlight recent advances in the diagnosis as well as in the identification of prognostic factors.
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PMID:[Cytomegalovirus (CMV) congenital infection]. 1833 44

X-linked Norrie disease, familial exudative vitreoretinopathy (FEVR), Coat's disease and retinopathy of prematurity are severe human eye diseases and can all be caused by mutations in the Norrie disease pseudoglioma gene. They all show vascular defects and characteristic features of retinal hypoxia. Only Norrie disease displays additional neurological symptoms, which are sensorineural hearing loss and mental retardation. In the present study, we analysed transcript levels of the ligand Norrin (Ndph) and its two receptors Frizzled-4 (Fzd4) and LDL-related protein receptor 5 (Lrp5) in six different brain regions (cerebellum, cortex, hippocampus, olfactory bulb, pituitary and brain stem) of 6- to 8-month-old wild-type and Ndph knockout mice by quantitative real-time PCR. No effect of the Ndph knockout allele on Fzd4 or Lrp5 receptor expression was found. Furthermore, no alterations of the transcript levels of three hypoxia-regulated angiogenic factors (Vegfa, Itgrb3 and Tie1) were observed in the absence of Norrin. Interestingly, we identified significant differences in Ndph, Fzd4 and Lrp5 transcript levels in brain regions of wild-type mice and observed highest expression of Norrin and frizzled-4 in cerebellum. Transcript analyses were correlated with morphological data obtained from cerebellum and immunohistochemical studies of blood vessels in different brain regions. Vessel density was reduced in the cerebellum of Ndph knockout mice but the number of Purkinje and granular cells was not altered. This provides the first description of a brain phenotype in Ndph knockout mice, which will help to elucidate the role of Norrin in the brain.
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PMID:Vascular changes in the cerebellum of Norrin /Ndph knockout mice correlate with high expression of Norrin and Frizzled-4. 1854 47

We describe a 14-year-old boy with congenital bilateral cataracts, blepharophimosis, ptosis, choanal atresia, sensorineural hearing loss, short, webbed neck, poor esophageal motility, severe growth and mental retardation, skeletal anomalies, seizures, and no speech. As an infant, he had transient hypogammaglobulinemia requiring IVIG therapy. Cytogenetic studies show an apparently de novo visible duplication at 1p36.3. Fluorescence in situ hybridization (FISH) studies confirm that the common region for the 1p36 deletion syndrome (p58) is duplicated. Probes for D1Z2 at 1p36.3 and the subtelomeric region of 1p (TEL1p) are also duplicated. Array comparative genomic hybridization (aCGH) studies were done at three separate laboratories, each with somewhat different results. BAC whole genome array CGH suggests a single clone gain at the 1p terminus and a single clone deletion at 1p36.3. A targeted BAC array panel with higher resolution at the distal 1p36 region detects a telomeric duplication and an interstitial deletion. Oligonucleotide whole genomic aCGH shows the highest resolution and a more complex rearrangement: two duplications, an interstitial deletion, and a normal region. The MMP23A/B "matrix metalloproteinase 23A/B" genes are within the distal duplication region in our patient, and this patient does not have craniosynostosis. This is the first association of congenital cataracts, choanal atresia, and transient immune abnormalities with 1p36 duplication/deletion. This case illustrates the limitations of different cytogenetic technologies, and shows how three separate aCGH platforms allow for refined delineation and interpretation of the complex cytogenetic rearrangement which would not have been discovered by standard high-resolution chromosome analysis.
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PMID:Cytogenetic and array CGH characterization of de novo 1p36 duplications and deletion in a patient with congenital cataracts, hearing loss, choanal atresia, and mental retardation. 1892 66

Mutations in several steps of de novo purine synthesis lead to human inborn errors of metabolism often characterized by mental retardation, hypotonia, sensorineural hearing loss, optic atrophy, and other features. In animals, the phosphoribosylglycinamide transformylase (GART) gene encodes a trifunctional protein carrying out 3 steps of de novo purine synthesis, phosphoribosylglycinamide synthase (GARS), phosphoribosylglycinamide transformylase (also abbreviated as GART), and phosphoribosylaminoimidazole synthetase (AIRS) and a smaller protein that contains only the GARS domain of GART as a functional protein. The GART gene is located on human chromosome 21 and is aberrantly regulated and overexpressed in individuals with Down syndrome (DS), and may be involved in the phenotype of DS. The GART activity of GART requires 10-formyltetrahydrofolate and has been a target for anti-cancer drugs. Thus, a considerable amount of information is available about GART, while less is known about the GARS and AIRS domains. Here we demonstrate that the amino acid residue glu75 is essential for the activity of the GARS enzyme and that the gly684 residue is essential for the activity of the AIRS enzyme by analysis of mutations in the Chinese hamster ovary (CHO-K1) cell that require purines for growth. We report the effects of these mutations on mRNA and protein content for GART and GARS. Further, we discuss the likely mechanisms by which mutations inactivating the GART protein might arise in CHO-K1 cells.
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PMID:Mutations in the Chinese hamster ovary cell GART gene of de novo purine synthesis. 1900 68

Johanson-Blizzard syndrome (JBS) is a rare autosomal recessive condition associated with exocrine pancreatic insufficiency, and is characterized by hypoplastic nasal alae, mental retardation, sensorineural hearing loss, short stature, scalp defects, dental abnormalities and abnormal hair patterns. Growth hormone deficiency, hypopituitarism, and impaired glucagon secretion response to insulin-induced hypoglycemia have been reported. Congenital heart defects have also been described in this condition. Mental retardation is typically moderate to severe in patients with JBS; however, normal intelligence can occur. In the pancreas, there is a selective defect of acinar tissue, whereas the islets of Langerhans and ducts are preserved. Diabetes has been reported in older children, suggesting the progressive nature of pancreatic disease. The molecular basis of JBS has recently been mapped to chromosome 15q15-q21 with identified mutations in the UBR1 gene. We report the case of a 7-year-old female with pancreatic insufficiency and mild phenotypic features, in whom the diagnosis of JBS was established using recently described molecular testing for the UBR1 gene.
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PMID:Johanson-Blizzard syndrome with mild phenotypic features confirmed by UBR1 gene testing. 1905 15


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