Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Disorders related to the autosomal transcription factor MEF2C located in 5q14.3 were first described in 2009 and have since evolved to one of the more common microdeletion syndromes. Mutational screening in a larger cohort revealed heterozygous de novo mutations of MEF2C in about 1% of patients with moderate to severe intellectual disability, and the phenotype is similar in patients with intragenic deletions and multigenic microdeletions. Clinically, MEF2C-related disorders are characterized by severe intellectual disability with absent speech and limited walking abilities, hypotonia, seizures, and a variety of minor brain anomalies. The majority of patients show a similar facial gestalt with broad forehead, flat nasal bridge, hypotonic mouth, and small chin, as well as strabismus, but this phenotype is clinically not well recognized. The course of the disease is generally quite uniform, but patients with point mutations and smaller deletions seem to have a higher chance of walking skills and a lower risk of refractory seizures. Patients in whom the microdeletion also includes the RASA1 gene show features of the respective capillary and arterio-venous malformations and fistula syndrome. The phenotypic overlap with Rett syndrome is explained by a shared pathway and, accordingly, diminished MECP2 and CDKL5 expression is measureable in patients with MEF2C defects. Further research of this pathway may therefore eventually lead to a common therapeutic target.
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PMID:The MEF2C-Related and 5q14.3q15 Microdeletion Syndrome. 2267 Jan 37

Up to now, only five-point mutations in the MEF2C gene have been described in patients with severe mental retardation with absent speech, limited walking abilities, epilepsy, and lack of gross malformations. In brain, MEF2C is essential for early neurogenesis, neuronal migration, and differentiation. Here, we present a new patient with severe mental retardation, epilepsy, and hand stereotypies associated with a novel MEF2C frameshift mutation c.457delA. The purpose of this work was to clarify criteria for the selection of patients with severe intellectual disability to screen for deficiency in the MEF2C gene. By combining the clinical data of all patients with MEF2C point mutations published so far with the phenotype of our patient, a targeted search for MEF2C mutations could be applied to patients with a severe intellectual deficiency associated with absence of language and hypotonia, strabismus, and epilepsy (started after 6 months, often well controlled by valproate).
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PMID:Refining the phenotype associated with MEF2C point mutations. 2300 26

Intellectual disability (ID) is frequent in the general population, with 1 in 50 individuals directly affected worldwide. The multiple etiologies include X-linked ID (XLID). Among syndromic XLID, few syndromes present severe ID associated with postnatal microcephaly and midline stereotypic hand movements. We report on three male patients with ID, midline stereotypic hand movements, hypotonia, hyperkinesia, strabismus, as well as seizures (2/3), and non-inherited and postnatal onset microcephaly (2/3). Using array CGH and exome sequencing we characterised two truncating mutations in IQSEC2, namely two de novo intragenic duplication mapped to the Xp11.22 region and a nonsense mutation in exon 7. We propose that truncating mutations in IQSEC2 are responsible for syndromic severe ID in male patients and should be screened in patients without mutations in MECP2, FOXG1, CDKL5 and MEF2C.
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PMID:Expanding the phenotype of IQSEC2 mutations: truncating mutations in severe intellectual disability. 2367 75