Connexion

GENATLAS PHENOTYPE

last update : 30-05-2012

Symbol	DEL17Q21
Location	17q21.31
Name	chromosome 17q21.31 microdeletion syndrome
Other name(s)	KANSL1-Related Intellectual Disability Syndrome; monosomy 17q21
Corresponding gene	MAPT , CRHR1 , KANSL1
Main clinical features	characteristic facial features: long face, tubular or pear-shaped nose with bulbous tip, friendly/amiable behavior low birth weigtht (<3rd centile), neonatal hypotonia, feeding problems in infants, developmental delay/mental retardation easily controlled seizures, heart defects and kidney/urologic anomalies ectodermal structures (skin, hair and teeth) frequently affected two families with sibling recurrence due to low-grade mosaicism, PMID: 22293690
Genetic determination	chromosomal
	genomic disorder
Prevalence	1 in 16 000 births
Function/system disorder	multisystem/generalized
	mental retardation
Type	MCA/MR

Gene product

Name

the KANSL1 protein is an evolutionarily conserved regulator of the chromatin modifier KAT8, which influences gene expression through histone H4 lysine 16 (H4K16) acetylation

Mechanism(s)

Gene mutation	Chromosome rearrangement	Effect	Comments

	deletion	haploinsufficiency	microdeletion with a critical region of 424kb
various types		haploinsufficiency	in the KANSL1 gene PMID: 22544367, PMID: 22544363

Remark(s)

several low-copy repeats, recently associated with a 900 kb inversion present in up to 20 percent of European subjects, are present in 17q21.31; this inversion is present in all examined parent originating the deletion ; the deleted region contains the MAPT gene, implicated in late onset neurodegenerative disorders, and other genes; haploinsufficiency of KANSL1 is sufficient to cause the classical 17q21.31 microdeletion syndrome phenotype PMID: 22544367,, PMID: 22544363 ;

Genotype/Phenotype correlations

patients carrying larger or non-overlapping deletions in this region have also been described with different manifestations