rs786204442

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PP2PP3PP5_Very_Strong

The NM_000478.6(ALPL):​c.791A>G​(p.Lys264Arg) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000372 in 1,613,930 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. 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. K264N) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

ALPL
NM_000478.6 missense, splice_region

Scores

1
8
10
Splicing: ADA: 0.9990
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 3.69

Publications

3 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 12 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000478.6
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
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
PP5
Variant 1-21568246-A-G is Pathogenic according to our data. Variant chr1-21568246-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188750.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.791A>G p.Lys264Arg missense_variant, splice_region_variant Exon 7 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.791A>G p.Lys264Arg missense_variant, splice_region_variant Exon 7 of 12 1 NM_000478.6 ENSP00000363973.3 P05186-1
ALPLENST00000374832.5 linkc.791A>G p.Lys264Arg missense_variant, splice_region_variant Exon 7 of 12 2 ENSP00000363965.1 P05186-1
ALPLENST00000540617.5 linkc.626A>G p.Lys209Arg missense_variant, splice_region_variant Exon 6 of 11 2 ENSP00000442672.1 P05186-3
ALPLENST00000539907.5 linkc.560A>G p.Lys187Arg missense_variant, splice_region_variant Exon 5 of 10 2 ENSP00000437674.1 P05186-2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152098
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000478
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461832
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727214
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.000115
AC:
3
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111994
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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

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:
0.0000131
AC:
2
AN:
152098
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74308
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.000288
AC:
1
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
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:
0.00
AC:
0
AN:
68006
Other (OTH)
AF:
0.000478
AC:
1
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
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:
0.0000564
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Childhood hypophosphatasia;C0268412:Infantile hypophosphatasia;C0268413:Adult hypophosphatasia Pathogenic:1
Apr 02, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Infantile hypophosphatasia Pathogenic:1
Apr 09, 2014
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

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
Dec 03, 2023
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hypophosphatasia Pathogenic:1
Oct 03, 2020
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: ALPL c.791A>G (p.Lys264Arg) located in the exonic-splice region of exon 7 results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. At least one publication reports experimental evidence that this variant affects mRNA splicing leading to a complete skipping of exon 7 (Brun-Heath_2007). The variant was absent in 251140 control chromosomes. c.791A>G has been reported in the literature in at-least one case of a baby girl affected with perinatal Hypophosphatasia (Brun-Heath_2007) as well as adults with this condition and subsequently cited by others (example, Taillandier_2018, Mornet_2008, Silvent_2014). These data indicate that the variant may be associated with disease. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided Pathogenic:1
May 13, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 264 of the ALPL protein (p.Lys264Arg). RNA analysis indicates that this missense change induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs786204442, gnomAD 0.3%). This missense change has been observed in individual(s) with autosomal recessive hypophosphatasia (PMID: 17922851). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 188750). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Studies have shown that this missense change results in skipping of exon 7, but is expected to preserve the integrity of the reading-frame (PMID: 17922851). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.074
BayesDel_addAF
Pathogenic
0.16
D
BayesDel_noAF
Uncertain
0.0
CADD
Pathogenic
28
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.61
D;.;.;D
Eigen
Benign
-0.090
Eigen_PC
Benign
-0.024
FATHMM_MKL
Benign
0.58
D
LIST_S2
Benign
0.79
.;T;T;T
M_CAP
Uncertain
0.22
D
MetaRNN
Uncertain
0.43
T;T;T;T
MetaSVM
Uncertain
0.66
D
MutationAssessor
Benign
1.0
L;.;.;L
PhyloP100
3.7
PrimateAI
Uncertain
0.49
T
PROVEAN
Benign
-0.80
N;N;N;N
REVEL
Uncertain
0.50
Sift
Benign
0.24
T;T;T;T
Sift4G
Benign
0.30
T;T;T;T
Polyphen
0.76
P;.;.;P
Vest4
0.55
MutPred
0.38
Loss of methylation at K264 (P = 0.0653);.;.;Loss of methylation at K264 (P = 0.0653);
MVP
0.96
MPC
0.89
ClinPred
0.80
D
GERP RS
4.0
Varity_R
0.11
gMVP
0.76
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.99
SpliceAI score (max)
0.32
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.32
Position offset: 1

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

Publications

Other links and lift over

dbSNP: rs786204442; hg19: chr1-21894739; API