Connexion

GENATLAS PHENOTYPE

last update : 23/12/2008

Symbol	DYT11
Location	7q21.3
HGNC id	3099
Name	dystonia 11, myoclonic
Other name(s)	myoclonic dystonia syndrome, myoclonus-dystonia
Corresponding gene	SGCE
Other symbol(s)	MCDT, MDS, M-D, DEL7Q21
Main clinical features	characterized by myoclonic and dystonic muscle contractions and the absence of other neurological signs, often alcohol-responsive early-onset myoclonus (shock-like jerks) commonly associated with focal or segmental dystonia and more infrequently, with psychiatric disturbances such as panic attacks and obsessive compulsive disorder
Genetic determination	autosomal dominant
	chromosomal
Related entries	including essential myoclonus
Function/system disorder	neurology
Type	disease

Gene product

Name

sarcoglycan epsilon

Mechanism(s)

Gene mutation	Chromosome rearrangement	Effect	Comments

deletion		truncated protein
missense		abnormal protein/loss of function	produce proteins that are retained intracellularly and degraded by the proteasome
nonsense		truncated protein	cause the premature termination of the protein; the most common nonsense mutation R102X truncates sarcoglycan before the transmembrane domain and produces low levels of protein possibly through nonsense-mediated decay of the mutant transcript
	deletion		genomic deletion including neighbouring genes such as COL1A2, or SHFM1, DLX6 and DLX5, or KRIT1, with variable phenotypic consequences (Asmus,07; Grunevald,08;Saugier-Veber 2010)

Remark(s)

the SGCE gene is maternally imprinted

Genotype/Phenotype correlations

reduced penetrance upon maternal transmission ; in large deletions including neighbouring genes typical M-D syndrome, but also short stature, microcephaly, and mental retardation, HEPACAM2, is a good candidate for both mental retardation and microcephaly (Saugier-Weber 2010);