Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deletion of the KANK1 gene (also called ANKRD15), located at chromosome position 9p24.3, has been associated with neurodevelopmental disease including congenital cerebral palsy, hypotonia, quadriplegia, and intellectual disability in a four-generation family. The inheritance pattern in this family was suggested to be maternal imprinting, as all affected individuals inherited the deletion from their fathers and monoallelic protein expression was observed. We present a family in which the proband's phenotype, including autism spectrum disorder, motor delay, and intellectual disability, is consistent with this previous report of KANK1 deletions. However, a paternally inherited deletion in the proband's unaffected sibling did not support maternal imprinting. This family raises consideration of further complexity of the KANK1 locus, including variable expressivity, incomplete penetrance, and the additive effects of additional genomic variants or the potential benign nature of inherited copy number variations (CNVs). However, when considered with the previous publication, our case also suggests that KANK1 may be subject to random monoallelic expression as a possible mode of inheritance. It is also important to consider that KANK1 has two alternately spliced transcripts, A and B. These have differential tissue expression and thus potentially differential clinical significance. Based upon cases in the literature, the present case, and information in the Database of Genomic Variants, it is possible that only aberrations of variant A contribute to neurodevelopmental disease. The familial deletion in this present case does not support maternal imprinting as an inheritance pattern. We suggest that other inheritance patterns and caveats should be considered when evaluating KANK1 deletions, which may become increasingly recognized through whole genome microarray testing, whole genome sequencing, and whole exome sequencing techniques.
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PMID:Familial KANK1 deletion that does not follow expected imprinting pattern. 2345 70

A small heterozygous deletion involving KANK1 was originally reported in 2005 to cause cerebral palsy in one large Israeli family of Jewish Moroccan origin. There were nine affected children over two generations to five unaffected fathers. All of these children had congenital hypotonia that evolved into spastic quadriplegia over the first year of life, along with intellectual impairment and brain atrophy. The subsequent clinical depictions of other individuals with neurological disease harbouring a comparable KANK1 deletion have been extremely variable and most often quite dissimilar to the original family. The reported pathogenicity of these deletions has also been variable, due to an inconsistent nature of reported disease associations and limited data. We therefore sought to perform a review of the significance of small distal interstitial chromosome 9p24.3 deletions principally involving KANK1, including data from the VCGS cytogenetics laboratory. We found that carrier parents do not appear to display an increased frequency of neurological disease, individuals with a small KANK1 deletion have sometimes been found to have an alternate genetic diagnosis that explained their neurological condition, and small KANK1 deletions can be seen with approximate equal frequency in case and control populations. These data led us to conclude that small deletions involving KANK1 do not cause a highly-penetrant influence of large effect size and they are unlikely to contribute significantly to the aetiology of disease in patients with development delay, intellectual disability, autism or cerebral palsy. We recommend searching for an alternate explanation for disease in individuals with a neurological disorder found to have a small deletion involving KANK1.
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PMID:Small interstitial 9p24.3 deletions principally involving KANK1 are likely benign copy number variants. 3068 69