Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011168 (dysphagia)
 15,644 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among the movement disorders associated with acanthocytosis, McLeod syndrome (McKusick 314850) is the one that is best characterized on the molecular level. Its defining feature is low reactivity of Kell erythrocyte antigens. This is due to absence of membrane protein KX that forms a complex with the Kell protein. KX is coded for by the XK gene on the X-chromosome. We present six males (aged 29 to 60 years), with proven XK mutations, to discuss the chorea associated with McLeod syndrome. The movement disorder commonly develops in the fifth decade and is progressive. It affects the limbs, the trunk and the face. In addition to facial grimacing, involuntary vocalization can be present. In early stages there may only be some restlessness or slight involuntary distal movements of ankles and fingers. Lip-biting and facial tics seem more common in autosomal recessive choreoacanthocytosis linked to chromosome 9. This, together with the absence of dysphagia in McLeod syndrome, may help in differential diagnosis. Recent findings suggest a role for the endothelin system of the striatum in the pathogenesis of McLeod syndrome.
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PMID:The chorea of McLeod syndrome. 1174 18

The clinical variability of Rett syndrome, associated with mutations in the MECP2 gene, varies from classically symptomatic female patients to asymptomatic female patients, and male patients who have none of the diagnostic features considered pathognomonic of this disease. Multiple factors contribute to this variability. In our studies, mutations closer to the amino-terminus, prior to amino acid 255, led to severe clinical manifestations, such as inability to walk, severe dysphagia, and urinary organic acid abnormalities, compared with mutations toward the carboxyl-terminus. However, we found no correlation between severity and mutation type (missense versus nonsense). Despite the importance of mutation location to clinical severity, the widely varying severity within the same mutation suggests that in females, X-chromosome inactivation or other epigenetic phenomena also have roles in determining severity. We propose that stages 1 and 2 of the disease are a consequence of failed, time-linked, postnatal expression of MeCP2 in cerebellar neurons. This, in association with glutamate N-methyl-D-aspartate receptor-mediated neuroexcitotoxic injury to the differentiating neurons, results in the transient age-specific autistic-like behavior, motor, and cognitive dysfunction associated with these stages.
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PMID:Clinical variability in Rett syndrome. 1464 46