1-21568111-TG-TGG

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000478.6(ALPL):c.662dupG(p.Gly222TrpfsTer10) variant causes a frameshift change. The variant allele was found at a frequency of 0.000000684 in 1,461,826 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

ALPL
NM_000478.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 5.19

Publications

1 publications found

Variant links:

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]

ALPL Gene-Disease associations (from GenCC):

adult hypophosphatasia
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, PanelApp Australia, Labcorp Genetics (formerly Invitae), Orphanet
childhood hypophosphatasia
Inheritance: AR, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, ClinGen, Orphanet
hypophosphatasia
Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, G2P
infantile hypophosphatasia
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae), PanelApp Australia
odontohypophosphatasia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
perinatal lethal hypophosphatasia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ALPL links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-21568111-T-TG is Pathogenic according to our data. Variant chr1-21568111-T-TG is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 370379.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALPL	NM_000478.6 link	c.662dupG	p.Gly222TrpfsTer10	frameshift_variant	Exon 7 of 12	ENST00000374840.8	NP_000469.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
ALPL	ENST00000374840.8 link	c.662dupG	p.Gly222TrpfsTer10	frameshift_variant	Exon 7 of 12	1	NM_000478.6	ENSP00000363973.3
ALPL	ENST00000374832.5 link	c.662dupG	p.Gly222TrpfsTer10	frameshift_variant	Exon 7 of 12	2		ENSP00000363965.1
ALPL	ENST00000540617.5 link	c.497dupG	p.Gly167TrpfsTer10	frameshift_variant	Exon 6 of 11	2		ENSP00000442672.1
ALPL	ENST00000539907.5 link	c.431dupG	p.Gly145TrpfsTer10	frameshift_variant	Exon 5 of 10	2		ENSP00000437674.1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461826

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727212

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53384

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111986

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Jul 17, 2023

GeneDx

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Reported with a second ALPL variant, phase unknown, in a fetus with hypophosphatasia (Simon-Bouy et al., 2008); This variant is associated with the following publications: (PMID: 10737975, 27397505, 18925618) -

May 07, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in ALPL are known to be pathogenic (PMID: 3174660, 10679946, 19500388). This variant has been observed in a fetus with clinical features of hypophosphatasia (PMID: 18925618). This variant is also known as 662insG in the literature. ClinVar contains an entry for this variant (Variation ID: 370379). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gly222Trpfs*10) in the ALPL gene. It is expected to result in an absent or disrupted protein product. -

Infantile hypophosphatasia

Pathogenic:1

Jan 28, 2016

Counsyl

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Adult hypophosphatasia

Pathogenic:1

Nov 16, 2023

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

5.2

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over