rs781272386

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM5PP2PP3_StrongPP5_Very_Strong

The NM_000478.6(ALPL):​c.815G>A​(p.Arg272His) variant causes a missense change. The variant allele was found at a frequency of 0.00000682 in 1,613,918 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R272C) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

ALPL
NM_000478.6 missense

Scores

8
6
5

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 3.84

Publications

6 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_000478.6
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-21570326-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 13684.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 220 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 1.2672 (below the threshold of 3.09). Trascript score misZ: 1.9021 (below the threshold of 3.09). GenCC associations: The gene is linked to adult hypophosphatasia, infantile hypophosphatasia, odontohypophosphatasia, childhood hypophosphatasia, hypophosphatasia, perinatal lethal hypophosphatasia.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.983
PP5
Variant 1-21570327-G-A is Pathogenic according to our data. Variant chr1-21570327-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 495882.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
ALPLNM_000478.6 linkc.815G>A p.Arg272His missense_variant Exon 8 of 12 ENST00000374840.8 NP_000469.3 P05186-1A0A024RAB4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ALPLENST00000374840.8 linkc.815G>A p.Arg272His missense_variant Exon 8 of 12 1 NM_000478.6 ENSP00000363973.3 P05186-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152088
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251330
AF XY:
0.0000147
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461830
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
AN XY:
727218
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111972
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152088
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74278
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68002
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.408
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000104
Hom.:
0
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Mar 02, 2020
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate a damaging effect (Brun-Heath et al., 2005); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32160374, 29236161, 28663156, 19500388, 15694177) -

Nov 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 272 of the ALPL protein (p.Arg272His). This variant is present in population databases (rs781272386, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of autosomal dominant and recessive ALPL-related conditions (PMID: 15694177, 28663156, 29236161). This variant is also known as R255H. ClinVar contains an entry for this variant (Variation ID: 495882). 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) indicates that this missense variant is expected to disrupt ALPL protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ALPL function (PMID: 15694177). This variant disrupts the p.Arg272 amino acid residue in ALPL. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17253930, 18559907, 24276437, 24378058). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Feb 24, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The ALPL c.815G>A; p.Arg272His variant (rs781272386), also known as R255H, is reported in the literature in individuals affected with autosomal dominant and recessive hypophosphatasia (Brun-Heath 2005, Saglam 2017, Taillandier 2018). This variant is also reported in ClinVar (Variation ID: 495882) and is found in the non-Finnish European population with an allele frequency of 0.003% (4/129072 alleles) in the Genome Aggregation Database. Additionally, other variants at this codon (c.814C>T, p.Arg272Cys; c.815G>T, p.Arg272Leu) have been reported in individuals with ALPL- related conditions and are considered pathogenic (Del Angel 2020, Zhang 2021). Functional analyses of the variant protein show reduced enzyme activity (Brun-Heath 2005, Del Angel 2020). Computational analyses predict that this variant is deleterious (REVEL: 0.896). Based on available information, this variant is considered to be pathogenic. References: Brun-Heath I et al. Characterization of 11 novel mutations in the tissue non-specific alkaline phosphatase gene responsible for hypophosphatasia and genotype-phenotype correlations. Mol Genet Metab. 2005 Mar;84(3):273-7. PMID: 15694177. Del Angel G et al. Large-scale in vitro functional testing and novel variant scoring via protein modeling provide insights into alkaline phosphatase activity in hypophosphatasia. Hum Mutat. 2020 Jul;41(7):1250-1262. PMID: 32160374. Saglam H et al. Clinical and Genetic Findings of Turkish Hypophosphatasia Cases. J Clin Res Pediatr Endocrinol. 2017 Sep 1;9(3):229-236. PMID: 28663156. Taillandier A et al. Genetic analysis of adults heterozygous for ALPL mutations. J Bone Miner Metab. 2018 Nov;36(6):723-733. PMID: 29236161. Zhang L et al. Molecular diagnosis for 55 fetuses with skeletal dysplasias by whole-exome sequencing: A retrospective cohort study. Clin Genet. 2021 Aug;100(2):219-226. PMID: 33942288. -

Childhood hypophosphatasia;C0268412:Infantile hypophosphatasia;C0268413:Adult hypophosphatasia Pathogenic:1
Jun 18, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Osteogenesis imperfecta Pathogenic:1
Jun 14, 2022
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Infantile hypophosphatasia Pathogenic:1
May 09, 2018
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
Mar 19, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hypophosphatasia Pathogenic:1
Jul 12, 2017
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: The ALPL c.815G>A (p.Arg272His) variant (alternatively also known as R255H) involves the alteration of a conserved nucleotide, resulting in a missense change residing in the alkaline-phosphatase-like core domain (InterPro). 3/3 in silico tools predict damaging outcome for this variant. This variant was found in the large control database ExAC at a frequency of 0.0000083 (1/120878 control chromosomes), which does not exceed the estimated maximal expected allele frequency of a pathogenic ALPL variant (0.0035355). The variant has been identified in a homozgous patient with hypophosphatasia (HPP), with in vitro functional studies showing that residual enzyme activity is < 10% of WT levels (Brun-Heath_MGM_2005). In addition, molecular modeling suggests the variant lies within a conserved calcium-binding domain, which is supported by the fact that several variants at the same codon are found in HPP patients (R272C, R272L), suggesting the residue is critical for protein function. The variant has not been classified in reputable databases or by clinical diagnostics laboratories. Taken together, this variant is classified as likely pathogenic until additional HPP patients with the variant are identified. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.32
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.44
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.96
D;.;.;D
Eigen
Uncertain
0.52
Eigen_PC
Uncertain
0.51
FATHMM_MKL
Benign
0.70
D
LIST_S2
Benign
0.63
.;T;T;T
M_CAP
Pathogenic
0.45
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.0
M;.;.;M
PhyloP100
3.8
PrimateAI
Benign
0.43
T
PROVEAN
Uncertain
-3.7
D;D;D;D
REVEL
Pathogenic
0.90
Sift
Uncertain
0.013
D;D;D;D
Sift4G
Uncertain
0.012
D;D;D;D
Polyphen
0.99
D;.;.;D
Vest4
0.79
MutPred
0.94
Loss of MoRF binding (P = 0.0633);.;.;Loss of MoRF binding (P = 0.0633);
MVP
0.98
MPC
0.70
ClinPred
0.95
D
GERP RS
5.2
PromoterAI
-0.022
Neutral
Varity_R
0.61
gMVP
0.80
Mutation Taster
=4/96
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs781272386; hg19: chr1-21896820; COSMIC: COSV66375979; COSMIC: COSV66375979; API