Repeat Disorders
STR: CSNK1E_FRA22A_CGG
PMID 39107278 and 40751262 report 4 unrelated families with a heterozygous CGG expansion in the 5'UTR of CSNK1E at fragile site FRA22A. 3 probands had developmental and epileptic encephalopathy and 1 had progressive myoclonic epilepsy from age 10.
Analysis of 1000 Genomes ONT data (n=908) suggests a normal range up to 48 repeats (98.7% <20).
Neither paper proposes a pathogenic threshold. The affected proband had 745 repeats, her unaffected 18-year-old sister 980 and their unaffected mother 131. An affected DEE proband had ~430-700 repeats and an unaffected carrier mother ~500.
Hypermethylation with ~50% reduced expression in fibroblasts is suggested to be the mechanism. The same hypermethylation was found in 6/23,116 controls.
Further probands/families are required to confirm the gene-disease association.
Comment on list classification: Unaffected carriers occur throughout the expansion range and no pathogenic threshold exists, and not useful in the clinical diagnostic setting.
Sources: LiteratureCreated: 2 Sep 2026, 7:16 p.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
CSNK1E-related progressive myoclonic epilepsy and developmental and epileptic encephalopathy
Publications
Str: csnk1e_fra22a_cgg has been classified as Amber List (Moderate Evidence).
Str: csnk1e_fra22a_cgg has been classified as Amber List (Moderate Evidence).
STR: CSNK1E_FRA22A_CGG was added STR: CSNK1E_FRA22A_CGG was added to Repeat Disorders. Sources: Literature Mode of inheritance for STR: CSNK1E_FRA22A_CGG was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for STR: CSNK1E_FRA22A_CGG were set to 40751262; 39107278 Phenotypes for STR: CSNK1E_FRA22A_CGG were set to CSNK1E-related progressive myoclonic epilepsy and developmental and epileptic encephalopathy Review for STR: CSNK1E_FRA22A_CGG was set to AMBER