Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_004260.4(RECQL4):c.1131_1131+3delGGTA(p.Ala378fs) variant causes a frameshift, splice donor, splice region, intron change. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.
RECQL4 (HGNC:9949): (RecQ like helicase 4) The protein encoded by this gene is a DNA helicase that belongs to the RecQ helicase family. DNA helicases unwind double-stranded DNA into single-stranded DNAs and may modulate chromosome segregation. This gene is predominantly expressed in thymus and testis. Mutations in this gene are associated with Rothmund-Thomson, RAPADILINO and Baller-Gerold syndromes. [provided by RefSeq, Jan 2010]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-144515984-TTACC-T is Pathogenic according to our data. Variant chr8-144515984-TTACC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 406879.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant results in the deletion of part of exon 5 (c.1131_1131+3) of the RECQL4 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in RECQL4 are known to be pathogenic (PMID: 12734318, 12952869). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with RECQL4-related conditions. ClinVar contains an entry for this variant (Variation ID: 406879). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -