7-157367402-T-C

Variant names:

• chr7-157367402-T-C
• rs387907150
• NM_058246.4:c.265T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 7P and 1B. PM1 PM2 PM5 PP5 BP4

The NM_058246.4(DNAJB6):​c.265T>C​(p.Phe89Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F89I) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: DNAJB6 NM_058246.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 2.73
• Publications: 25 publications found

Genes affected

DNAJB6 (HGNC:14888): (DnaJ heat shock protein family (Hsp40) member B6) This gene encodes a member of the DNAJ protein family. DNAJ family members are characterized by a highly conserved amino acid stretch called the 'J-domain' and function as one of the two major classes of molecular chaperones involved in a wide range of cellular events, such as protein folding and oligomeric protein complex assembly. This family member may also play a role in polyglutamine aggregation in specific neurons. Alternative splicing of this gene results in multiple transcript variants; however, not all variants have been fully described. [provided by RefSeq, Jul 2008]

DNAJB6 Gene-Disease associations (from GenCC):

• muscular dystrophy, limb-girdle, autosomal dominant

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• autosomal dominant limb-girdle muscular dystrophy type 1D (DNAJB6)

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_058246.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-157367402-T-A is described in ClinVar as Pathogenic. ClinVar VariationId is 31531.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP5: Variant 7-157367402-T-C is Pathogenic according to our data. Variant chr7-157367402-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 427160.
• BP4: Computational evidence support a benign effect (MetaRNN=0.19515404). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DNAJB6	NM_058246.4	c.265T>C	p.Phe89Leu	missense_variant	Exon 5 of 10	ENST00000262177.9	NP_490647.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DNAJB6	ENST00000262177.9	c.265T>C	p.Phe89Leu	missense_variant	Exon 5 of 10	1	NM_058246.4	ENSP00000262177.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Autosomal dominant limb-girdle muscular dystrophy type 1D (DNAJB6) Pathogenic:1 Uncertain:1

Jun 27, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 89 of the DNAJB6 protein (p.Phe89Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with limb-girdle muscular dystrophy (internal data). ClinVar contains an entry for this variant (Variation ID: 427160). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on DNAJB6 protein function. This variant disrupts the p.Phe89 amino acid residue in DNAJB6. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 22366786, 24594375, 24920671, 26371419). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not provided Pathogenic:1

May 11, 2015

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The F89L variant has not been published as a pathogenic variant, nor has it been reported as a benign polymorphism to our knowledge. However, a different amino acid substitution at the same residue (F89I) has been reported in two large families with LGMD1D (Sarparanta et al., 2012, Couthouis et al., 2014). Functional studies showed that F89L increased the half-life of the DNAJB6 protein and reduced its anti-aggregation properties (Sarparanta et al., 2012). F89L was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. This substitution occurs at a position that is conserved in mammals and is predicted to be within the G/F domain where all LGMD1D-associated variants have been reported (Sato et al., 2013; Harms et al., 2012). Therefore, this variant is a strong candidate for a pathogenic variant, however the possibility that it is a benign variant cannot be excluded. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Uncertain	0.032	T
BayesDel_noAF	Benign	-0.19
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Benign	0.092	T;.;D;.;T;.;T;T
Eigen	Benign	0.13
Eigen_PC	Benign	0.18
FATHMM_MKL	Benign	0.71	D
LIST_S2	Benign	0.70	T;T;T;T;T;T;T;T
M_CAP	Benign	0.044	D
MetaRNN	Benign	0.20	T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.41	T
MutationAssessor	Pathogenic	3.1	.;M;M;.;.;.;.;.
PhyloP100		2.7
PrimateAI	Uncertain	0.68	T
PROVEAN	Uncertain	-4.2	D;D;D;D;D;D;D;.
REVEL	Benign	0.28
Sift	Benign	0.034	D;T;D;T;D;D;T;.
Sift4G	Benign	0.074	T;T;T;T;D;T;T;T
Polyphen		0.0040, 0.89, 0.31	.;B;P;.;B;.;.;.
Vest4		0.58, 0.59, 0.57, 0.59
MutPred		0.27		Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);Gain of relative solvent accessibility (P = 0.1571);
MVP		0.78
MPC		0.90
ClinPred		0.96	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.42
gMVP		0.89
Mutation Taster		=29/71	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs387907150; hg19: chr7-157160096;