Early onset or syndromic epilepsy

STR: SAMD12_TTTCA

Green List (high evidence)

The TTTCA repeat is present in conjunction with TTTTA repeats in patients with OMIM:601068. Ishiura et al., 2018 (PMID: 29507423). In patients the expansions TTTCA and TTTTA combined was estimated to be in the range of 440 to 3680 repeats (one patient had 598 repeats of TTTTA and 458 repeats of TTTCA). In 82 patients the configuration of expansion was interpreted as: (TTTTA)exp(TTTCA)exp and in one family it was given as: (TTTTA)exp(TTTCA)exp(TTTTA)exp. There were no reports of TTTCA expansions in controls, however, 5.9% of healthy individuals had TTTTA expansions, therefore suggesting that the TTTTA expansion does no contribute to the disease (Ishiura et al., 2018).

Created: 1 Apr 2025, 2:36 p.m. | Last Modified: 1 Apr 2025, 2:36 p.m.

Panel Version: 7.84

SAMD12 transcribed from the reverse strand, which means that the repeated sequence is the reverse compliment of the forward strand sequence.

SAMD12_TTTCA is on https://gnomad.broadinstitute.org/short-tandem-repeats?dataset=gnomad_r3

SAMD12_TTTCA is on https://stripy.org/database

SAMD12_TTTTA is on DRAGON 4.02.

The coordinates of the sequence repeats shown above were obtained from DRAGON 4.02
The coordinates https://gnomad.broadinstitute.org/short-tandem-repeats?dataset=gnomad_r4 and https://stripy.org/database were 8:118366815-118366913 (hg38)

The non-pathogenic and pathogenic ranges of the sequence repeats shown above were obtained from: https://stripy.org/database

There is enough evidence for this STR to be green on this panel.

This STR has not been approved by NHS STR working group and is not NGS Not Validated
Sources: Literature

Created: 1 Apr 2025, 2:13 p.m. | Last Modified: 1 Apr 2025, 2:58 p.m.

Panel Version: 7.84

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

Publications

• 30194086
• 29507423
• 29939203
• 32203200