1-21568242-T-G

Position:

• chr1-21568242-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000478.6(ALPL):​c.787T>G​(p.Tyr263Asp) 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. 13/21 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. Y263H) has been classified as Benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: ALPL NM_000478.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0570

Genes affected

ALPL (HGNC:438): (alkaline phosphatase, biomineralization associated) This gene encodes a member of the alkaline phosphatase family of proteins. There are at least four distinct but related alkaline phosphatases: intestinal, placental, placental-like, and liver/bone/kidney (tissue non-specific). The first three are located together on chromosome 2, while the tissue non-specific form is located on chromosome 1. The product of this gene is a membrane bound glycosylated enzyme that is not expressed in any particular tissue and is, therefore, referred to as the tissue-nonspecific form of the enzyme. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate the mature enzyme. This enzyme may play a role in bone mineralization. Mutations in this gene have been linked to hypophosphatasia, a disorder that is characterized by hypercalcemia and skeletal defects. [provided by RefSeq, Oct 2015]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000478.6
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10351989).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALPL	NM_000478.6	c.787T>G	p.Tyr263Asp	missense_variant	7/12	ENST00000374840.8	NP_000469.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALPL	ENST00000374840.8	c.787T>G	p.Tyr263Asp	missense_variant	7/12	1	NM_000478.6	ENSP00000363973.3
ALPL	ENST00000374832.5	c.787T>G	p.Tyr263Asp	missense_variant	7/12	2		ENSP00000363965.1
ALPL	ENST00000540617.5	c.622T>G	p.Tyr208Asp	missense_variant	6/11	2		ENSP00000442672.1
ALPL	ENST00000539907.5	c.556T>G	p.Tyr186Asp	missense_variant	5/10	2		ENSP00000437674.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.057
BayesDel_addAF	Uncertain	0.062	T
BayesDel_noAF	Benign	-0.15
CADD	Benign	7.9
DANN	Benign	0.71
DEOGEN2	Uncertain	0.56	D;.;.;D
Eigen	Benign	-0.98
Eigen_PC	Benign	-0.89
FATHMM_MKL	Benign	0.027	N
LIST_S2	Benign	0.057	.;T;T;T
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.10	T;T;T;T
MetaSVM	Benign	-0.34	T
MutationAssessor	Benign	-0.81	N;.;.;N
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-0.40	N;N;N;N
REVEL	Uncertain	0.34
Sift	Benign	0.32	T;T;T;T
Sift4G	Benign	0.64	T;T;T;T
Polyphen		0.0	B;.;.;B
Vest4		0.16
MutPred		0.29		Gain of disorder (P = 0.0182);.;.;Gain of disorder (P = 0.0182);
MVP		0.79
MPC		0.72
ClinPred		0.19	T
GERP RS		1.9
Varity_R		0.061
gMVP		0.78

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: rs3200254; hg19: chr1-21894735;