4-87656493-A-G

Position:

• chr4-87656493-A-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_004407.4(DMP1):​c.1A>G​(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.00000344 in 1,453,326 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: DMP1 NM_004407.4 start_lost
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 B:1
• Conservation: PhyloP100: 3.81

Genes affected

DMP1 (HGNC:2932): (dentin matrix acidic phosphoprotein 1) Dentin matrix acidic phosphoprotein is an extracellular matrix protein and a member of the small integrin binding ligand N-linked glycoprotein family. This protein, which is critical for proper mineralization of bone and dentin, is present in diverse cells of bone and tooth tissues. The protein contains a large number of acidic domains, multiple phosphorylation sites, a functional arg-gly-asp cell attachment sequence, and a DNA binding domain. In undifferentiated osteoblasts it is primarily a nuclear protein that regulates the expression of osteoblast-specific genes. During osteoblast maturation the protein becomes phosphorylated and is exported to the extracellular matrix, where it orchestrates mineralized matrix formation. Mutations in the gene are known to cause autosomal recessive hypophosphatemia, a disease that manifests as rickets and osteomalacia. The gene structure is conserved in mammals. Two transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Start lost variant, no new inframe start found.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DMP1	NM_004407.4	c.1A>G	p.Met1?	start_lost	2/6	ENST00000339673.11	NP_004398.1
DMP1	NM_001079911.3	c.1A>G	p.Met1?	start_lost	2/5		NP_001073380.1
DMP1	XM_011531705.3	c.88A>G	p.Met30Val	missense_variant	2/6		XP_011530007.1
DMP1	XM_011531706.3	c.88A>G	p.Met30Val	missense_variant	2/5		XP_011530008.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DMP1	ENST00000339673.11	c.1A>G	p.Met1?	start_lost	2/6	1	NM_004407.4	ENSP00000340935	P1
	ENST00000506480.5	n.322+16497T>C		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251412 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135878

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000344 AC: 5 AN: 1453326 Hom.: 0 Cov.: 29 AF XY: 0.00000553 AC XY: 4 AN XY: 723776

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000181

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000422 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Oct 01, 2015

The c.1 A>G pathogenic variant in the DMP1 gene has been reported previously in the homozygous state and segregated in a family with hypophatemic rickets (Feng et al., 2006). The c.1 A>G variant results in loss of a highly conserved sequence that affects appropriate signalling to the trans-Golgi network (Feng et al., 2006; Farrow et al., 2009). As this pathogenic variant changes the translation initiator Methionine codon, the resultant protein is described as p.Met1?, using a question mark to signify that it is not known if the loss of Met1 means that all protein translation is completely prevented or if an abnormal protein is produced using an alternate Methionine. The c.1 A>G variant 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. We interpret c.1 A>G as a pathogenic variant. -

Hypophosphatemic rickets, autosomal recessive, 1 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 2006

- -

not specified Benign:1

Benign, criteria provided, single submitter

research

Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center

Jan 12, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.077	T;.
Eigen	Benign	0.076
Eigen_PC	Benign	0.086
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Benign	-0.69	T
MutationTaster	Benign	0.43	A;A
PROVEAN	Benign	-0.42	N;N
REVEL	Uncertain	0.30
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.75	P;P
Vest4		0.68
MutPred		0.88		Gain of methylation at K2 (P = 0.0231);Gain of methylation at K2 (P = 0.0231);
MVP		0.77
ClinPred		0.99	D
GERP RS		4.4
Varity_R		0.81
gMVP		0.25

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: rs104893834; hg19: chr4-88577645;