rs281865142

Variant names:

• chr11-111908948-GA-G
• rs281865142
• NM_001289808.2:c.343delT

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PVS1_Strong PS3 PP5

The NM_001289808.2(CRYAB):​c.343delT​(p.Ser115ProfsTer14) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000991 in 1,613,966 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). ClinVar reports functional evidence for this variant: "SCV000235760: Published functional studies demonstrate a damaging effect as induced pluripotent stem cells (iPSC) derived from fibroblasts from an infant with myofibrillar myopathy showed that this variant causes protein insolubility, resulting in the loss of alpha-B-crystallin protein expression in iPSC-derived skeletal myotubes and cardiomyocytes (Mitzelfelt et al., 2016)" and additional evidence is available in ClinVar. Synonymous variant affecting the same amino acid position (i.e. S115S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: CRYAB NM_001289808.2 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5 U:1 O:1
• Conservation: PhyloP100: 5.29
• Publications: 13 publications found

Genes affected

CRYAB (HGNC:2389): (crystallin alpha B) Mammalian lens crystallins are divided into alpha, beta, and gamma families. Alpha crystallins are composed of two gene products: alpha-A and alpha-B, for acidic and basic, respectively. Alpha crystallins can be induced by heat shock and are members of the small heat shock protein (HSP20) family. They act as molecular chaperones although they do not renature proteins and release them in the fashion of a true chaperone; instead they hold them in large soluble aggregates. These heterogeneous aggregates consist of 30-40 subunits; the alpha-A and alpha-B subunits have a 3:1 ratio, respectively. Two additional functions of alpha crystallins are an autokinase activity and participation in the intracellular architecture. The encoded protein has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. Alpha-A and alpha-B gene products are differentially expressed; alpha-A is preferentially restricted to the lens and alpha-B is expressed widely in many tissues and organs. Elevated expression of alpha-B crystallin occurs in many neurological diseases; a missense mutation cosegregated in a family with a desmin-related myopathy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2019]

CRYAB Gene-Disease associations (from GenCC):

• myofibrillar myopathy 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet
• cataract 16 multiple types

  Inheritance: AR, AD Classification: STRONG, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• fatal infantile hypertonic myofibrillar myopathy

  Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• early-onset lamellar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset nuclear cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset posterior polar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy 1II

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 8 pathogenic variants in the truncated region.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000235760: Published functional studies demonstrate a damaging effect as induced pluripotent stem cells (iPSC) derived from fibroblasts from an infant with myofibrillar myopathy showed that this variant causes protein insolubility, resulting in the loss of alpha-B-crystallin protein expression in iPSC-derived skeletal myotubes and cardiomyocytes (Mitzelfelt et al., 2016); SCV000822704: Experimental studies have shown that this premature translational stop signal affects CRYAB function (PMID: 21130652, 27226619).
• PP5: Variant 11-111908948-GA-G is Pathogenic according to our data. Variant chr11-111908948-GA-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 38963.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001289808.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CRYAB	NM_001289808.2	MANE Select	c.343delT	p.Ser115ProfsTer14	frameshift	Exon 3 of 3	NP_001276737.1	P02511
	CRYAB	NM_001289807.1		c.343delT	p.Ser115ProfsTer14	frameshift	Exon 4 of 4	NP_001276736.1	P02511
	CRYAB	NM_001368245.1		c.343delT	p.Ser115ProfsTer14	frameshift	Exon 4 of 4	NP_001355174.1	P02511

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CRYAB	ENST00000650687.2	MANE Select	c.343delT	p.Ser115ProfsTer14	frameshift	Exon 3 of 3	ENSP00000499082.1	P02511
	CRYAB	ENST00000526180.6	TSL:1	c.343delT	p.Ser115ProfsTer14	frameshift	Exon 4 of 4	ENSP00000436051.1	P02511
	CRYAB	ENST00000227251.7	TSL:5	c.343delT	p.Ser115ProfsTer14	frameshift	Exon 4 of 4	ENSP00000227251.3	P02511

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152104 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250916 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1461862 Hom.: 0 Cov.: 31 AF XY: 0.00000825 AC XY: 6 AN XY: 727236

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000989 AC: 11 AN: 1111998

Other (OTH) AF: 0.0000331 AC: 2 AN: 60396

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152104 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74312

African (AFR) AF: 0.0000483 AC: 2 AN: 41400

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4816

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2084

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (3)
-	1	-	Cardiovascular phenotype (1)
1	-	-	Dilated cardiomyopathy 1II (1)
1	-	-	Myofibrillar myopathy 2;C3554649:Dilated cardiomyopathy 1II;C3808377:Cataract 16 multiple types;C5190691:Fatal infantile hypertonic myofibrillar myopathy (1)
-	-	-	Myofibrillar myopathy 2 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.3
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs281865142; hg19: chr11-111779672;