rs1555425082

chr15-90811287-A-Gchr15-90811287-A-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000057.4(BLM):c.3957A>G(p.Ile1319Met) 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. 15/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I1319V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BLM NM_000057.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.76

Genes affected

BLM (HGNC:1058): (BLM RecQ like helicase) The Bloom syndrome is an autosomal recessive disorder characterized by growth deficiency, microcephaly and immunodeficiency among others. It is caused by homozygous or compound heterozygous mutation in the gene encoding DNA helicase RecQ protein on chromosome 15q26. This Bloom-associated helicase unwinds a variety of DNA substrates including Holliday junction, and is involved in several pathways contributing to the maintenance of genome stability. Identification of pathogenic Bloom variants is required for heterozygote testing in at-risk families. [provided by RefSeq, May 2020]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.04695207).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BLM	NM_000057.4	c.3957A>G	p.Ile1319Met	missense_variant	21/22	ENST00000355112.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BLM	ENST00000355112.8	c.3957A>G	p.Ile1319Met	missense_variant	21/22	1	NM_000057.4	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.061
BayesDel_addAF	Benign	-0.31	T
BayesDel_noAF	Benign	-0.68
Cadd	Benign	0.046
Dann	Benign	0.088
DEOGEN2	Benign	0.068	T;.
Eigen	Benign	-1.7
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.016	N
LIST_S2	Benign	0.49	T;T
M_CAP	Benign	0.0057	T
MetaRNN	Benign	0.047	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.69	N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	0.11	N;N
REVEL	Benign	0.054
Sift	Benign	0.24	T;D
Sift4G	Benign	0.20	T;T
Polyphen		0.0010	B;.
Vest4		0.039
MutPred		0.19		Loss of helix (P = 0.079);.;
MVP		0.38
MPC		0.091
ClinPred		0.051	T
GERP RS		-12
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.026
gMVP		0.10

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555425082; hg19: chr15-91354517;