Ataxia - paediatric

Gene: CSTB

Green List (high evidence)

Myoclonic epilepsy of Unverricht and Lundborg is an autosomal recessive disorder characterized by onset of neurodegeneration between 6 and 13 years of age. It is typically progressive in adolescence, with dramatic worsening of myoclonus and ataxia in the first 6 years after onset. The disease stabilises in early adulthood, and myoclonus and ataxia may even improve, and there is minimal to no cognitive decline.

Note the most common causative allele is a dodecamer repeat in the promoter region. Missense variants have been reported, most commonly compound het with the repeat, except for p.Gly4Arg which has been reported in the homozygous state also.

Created: 12 Sep 2020, 2:55 a.m. | Last Modified: 12 Sep 2020, 3:05 a.m.

Panel Version: 0.233

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Epilepsy, progressive myoclonic 1A (Unverricht and Lundborg), MIM# 254800

Publications

• 9012407
• 9054946

I don't know

PMID: 28457472; CNV
- 7 South African families with keratolytic winter erythema. Identified a noncoding 7.67-kb tandem duplication on chromosome 8 that segregated with disease and was not found in 127 controls.
- This region overlaps with an enhancer element which correlated with CTSB expression
- qPCR analysis and immunohistochemistry of the palmar epidermis demonstrated significantly increased expression of CTSB, as well as stronger staining of cathepsin B in the stratum granulosum of affected individuals than in that of control

Created: 10 Aug 2020, 6:25 a.m. | Last Modified: 10 Aug 2020, 6:25 a.m.

Panel Version: 0.3743

Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown

Phenotypes
Keratolytic winter erythema (MIM#148370)

Publications

• 28457472