rs140108514
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PS1PM3_StrongPVS1_ModeratePP4_Strong
This summary comes from the ClinGen Evidence Repository: The NM_003494.4: c.2643+1G>A variant in DYSF, which is also known as NM_001130987.2: c.2697+1G>A, occurs within the canonical splice donor site of intron 25. It is predicted to cause skipping of biologically relevant exon 25/55, resulting in an in-frame deletion of 44 amino acids. Skipping of exon 25 was confirmed by minigene assay and RNAseq (PMID 25312915, 36983702; PVS1_Moderate_RNA). This variant has been detected in at least eight unrelated individuals with LGMD (PMID:30564623, 36983702, 33927379, 23243261, 22246893, 18853459). Of these individuals, four were homozygous (1.0 pt), and four were compound heterozygous; in at least two cases, the variant was confirmed in trans with a pathogenic or likely pathogenic variant (c.1948delC p.(Leu650TyrfsTer6), 1.0 pt; c.4497delT p.(Phe1499LeufsTer4), 1.0 pt) (PM3_Strong). At least one of these patients displayed a progressive limb girdle pattern of muscle weakness and absent dysferlin expression in skeletal muscle and/or blood monocytes, which is highly specific for DYSF-related LGMD (PP4_Strong; PMID:36983702, 33927379). The filtering allele frequency for this variant is 0.001335 in gnomAD v2.1.1 African/African American genomes (the lower threshold of the 95% CI of 18/8708), which is higher than the LGMD VCEP threshold of 0.001 for BS1; however, this variant is a frequently observed variant among patients, and the VCEP opted not to apply this code (BS1 exception). Another nucleotide change affecting the same splice site and with the same predicted splice effect, NM_003494.4: c.2643+1G>C, is classified as pathogenic for autosomal recessive limb girdle muscular dystrophy by the ClinGen LGMD VCEP (PS1). In summary, this variant meets the threshold for the criteria to be classified as Pathogenic for autosomal recessive limb girdle muscular dystrophy by the ClinGen LGMD VCEP. Although the population frequency of this variant provides benign evidence, the VCEP considers this not inconsistent with the final classification given the frequency at which it is observed in the patient population. ACMG/AMP criteria applied, as specified by the ClinGen LGMD VCEP (LGMD VCEP specifications version 1.0.0; 01/08/2025): PVS1_Moderate_RNA, PS1, PM3_Strong, PP4_Strong. LINK:https://erepo.genome.network/evrepo/ui/classification/CA222141/MONDO:0015152/180
Frequency
Consequence
NM_001130987.2 splice_donor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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DYSF | NM_001130987.2 | c.2697+1G>A | splice_donor_variant, intron_variant | Intron 25 of 55 | ENST00000410020.8 | NP_001124459.1 | ||
DYSF | NM_003494.4 | c.2643+1G>A | splice_donor_variant, intron_variant | Intron 25 of 54 | ENST00000258104.8 | NP_003485.1 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
DYSF | ENST00000410020.8 | c.2697+1G>A | splice_donor_variant, intron_variant | Intron 25 of 55 | 1 | NM_001130987.2 | ENSP00000386881.3 | |||
DYSF | ENST00000258104.8 | c.2643+1G>A | splice_donor_variant, intron_variant | Intron 25 of 54 | 1 | NM_003494.4 | ENSP00000258104.3 |
Frequencies
GnomAD3 genomes AF: 0.000421 AC: 64AN: 152174Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.000115 AC: 29AN: 251492Hom.: 0 AF XY: 0.0000662 AC XY: 9AN XY: 135918
GnomAD4 exome AF: 0.0000390 AC: 57AN: 1461894Hom.: 0 Cov.: 36 AF XY: 0.0000289 AC XY: 21AN XY: 727248
GnomAD4 genome AF: 0.000421 AC: 64AN: 152174Hom.: 0 Cov.: 33 AF XY: 0.000404 AC XY: 30AN XY: 74324
ClinVar
Submissions by phenotype
not provided Pathogenic:5
Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown.; Published minigene assays show that this canonical splice variant results in the skipping of exon 25, suggesting that it results in abnormal splicing (Kergourlay et al., 2014); This variant is associated with the following publications: (PMID: 22246893, 25525159, 23243261, 12796534, 11532985, 18853459, 29382405, 31980526, 31589614, 33610434, 24438169, 25312915) -
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This variant is expected to severely impact normal RNA splicing, and consequently, protein structure and/or function. The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). In multiple individuals, including cases of Miyoshi myopathy and limb girdle muscular dystrophy, this variant has been seen with a single recessive pathogenic variant in the same gene, suggesting this variant may also be pathogenic. This variant is also referred to as c.2697+1G>A and c.3016+1G>A in published literature. Assessment of experimental evidence suggests this variant results in abnormal protein function. This variant has been shown to cause exon skipping (PMID: 25312915). -
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PM2_moderate, PM3_very_strong, PS4_moderate, PVS1_moderate -
Autosomal recessive limb-girdle muscular dystrophy type 2B Pathogenic:3
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The heterozygous c.2697+1G>A variant in DYSF was identified by our study in one individual in the compound heterozygous state, with another pathogenic variant, in one individual with limb-girdle muscular dystrophy (LGMD). This variant has been identified in 0.1706% (41/24026) of African chromosomes in the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs140108514). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. The c.2697+1G>A variant in DYSF has been reported in 3 individuals with LGMD (PMID: 23243261). The presence of this variant in combination with reported pathogenic variants and in 2 individuals with LGMD increases the likelihood that the c.2697+1G>A variant is pathogenic. In vitro functional studies provide some evidence that the c.2697+1G>A variant may impact protein function by causing abnormal splicing of Exon 25 (PMID: 25312915). However, these types of assays may not accurately represent biological function.This variant occurs in the invariant region (+/- 1/2) of the splice consensus sequence and is predicted to cause altered splicing leading to an in-frame transcript deletion and abnormal or absent protein. Loss of function In the DYSF gene is an established disease mechanism in autosomal recessive LGMD. In summary, the clinical significance of the 2697+1G>A variant is pathogenic. ACMG/AMP Criteria applied: PVS1_Moderate, PS3, PM3_Strong (Richards 2015). -
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Distal myopathy with anterior tibial onset;C1850889:Autosomal recessive limb-girdle muscular dystrophy type 2B;C4551973:Miyoshi muscular dystrophy 1 Pathogenic:2
NM_003494.3(DYSF):c.2643+1G>A is a canonical splice variant classified as pathogenic in the context of dysferlinopathy. c.2643+1G>A has been observed in cases with relevant disease (PMID: 30564623, 12796534, 23243261, 27854218, 18832576, 24488599, 21816046). Functional assessments of this variant are available in the literature (PMID: 25312915). c.2643+1G>A has been observed in population frequency databases (gnomAD: AFR 0.13%). In summary, NM_003494.3(DYSF):c.2643+1G>A is a canonical splice variant in a gene where loss of function is a known mechanism of disease, is predicted to disrupt protein function, and has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
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Miyoshi muscular dystrophy 1 Pathogenic:2
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Autosomal recessive limb-girdle muscular dystrophy Pathogenic:1
The NM_003494.4: c.2643+1G>A variant in DYSF, which is also known as NM_001130987.2: c.2697+1G>A, occurs within the canonical splice donor site of intron 25. It is predicted to cause skipping of biologically relevant exon 25/55, resulting in an in-frame deletion of 44 amino acids. Skipping of exon 25 was confirmed by minigene assay and RNAseq (PMID 25312915, 36983702; PVS1_Moderate_RNA). This variant has been detected in at least eight unrelated individuals with LGMD (PMID: 30564623, 36983702, 33927379, 23243261, 22246893, 18853459). Of these individuals, four were homozygous (1.0 pt), and four were compound heterozygous; in at least two cases, the variant was confirmed in trans with a pathogenic or likely pathogenic variant (c.1948delC p.(Leu650TyrfsTer6), 1.0 pt; c.4497delT p.(Phe1499LeufsTer4), 1.0 pt) (PM3_Strong). At least one of these patients displayed a progressive limb girdle pattern of muscle weakness and absent dysferlin expression in skeletal muscle and/or blood monocytes, which is highly specific for DYSF-related LGMD (PP4_Strong; PMID: 36983702, 33927379). The filtering allele frequency for this variant is 0.001335 in gnomAD v2.1.1 African/African American genomes (the lower threshold of the 95% CI of 18/8708), which is higher than the LGMD VCEP threshold of 0.001 for BS1; however, this variant is a frequently observed variant among patients, and the VCEP opted not to apply this code (BS1 exception). Another nucleotide change affecting the same splice site and with the same predicted splice effect, NM_003494.4: c.2643+1G>C, is classified as pathogenic for autosomal recessive limb girdle muscular dystrophy by the ClinGen LGMD VCEP (PS1). In summary, this variant meets the threshold for the criteria to be classified as Pathogenic for autosomal recessive limb girdle muscular dystrophy by the ClinGen LGMD VCEP. Although the population frequency of this variant provides benign evidence, the VCEP considers this not inconsistent with the final classification given the frequency at which it is observed in the patient population. ACMG/AMP criteria applied, as specified by the ClinGen LGMD VCEP (LGMD VCEP specifications version 1.0.0; 01/08/2025): PVS1_Moderate_RNA, PS1, PM3_Strong, PP4_Strong. -
DYSF-related disorder Pathogenic:1
The DYSF c.2643+1G>A variant is predicted to disrupt the GT donor site and interfere with normal splicing. This variant has been reported in the homozygous or compound heterozygous state in patients diagnosed with limb-girdle muscular dystrophy type 2B (LGMD2B) or Miyoshi myopathy (Krahn et al. 2009. PubMed ID: 18853459; Takahashi et al. 2013. PubMed ID: 23243261). In a mini-gene assay, the c.2643+1G>A variant led to exon skipping (Kergourlay et al. 2014. PubMed ID: 25312915). This variant has been reported at an allele frequency of ~0.2% in an African population; in other ethnicities it is absent or reported less frequently (i.e. <0.01%) (http://gnomad.broadinstitute.org/variant/2-71795213-G-A). Variants that disrupt the consensus splice donor site in DYSF are expected to be pathogenic. This variant is interpreted as pathogenic. -
Qualitative or quantitative defects of dysferlin Pathogenic:1
This sequence change affects a donor splice site in intron 25 of the DYSF gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs140108514, gnomAD 0.2%). Disruption of this splice site has been observed in individuals with autosomal recessive limb-girdle muscular dystrophy and Miyoshi myopathy (PMID: 12796534, 18853459, 21816046, 22246893, 23243261, 27854218). This variant is also known as G3016+1A and c.3016+1G>A. ClinVar contains an entry for this variant (Variation ID: 94291). Studies have shown that disruption of this splice site results in skipping of exon 25, but is expected to preserve the integrity of the reading-frame (PMID: 25312915). For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at