rs374894037

Variant summary

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

The NM_001253852.3(AP4B1):​c.1177C>T​(p.Arg393*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000621 in 1,609,488 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R393R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

AP4B1
NM_001253852.3 stop_gained

Scores

4
2
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 3.09

Publications

2 publications found
Variant links:
Genes affected
AP4B1 (HGNC:572): (adaptor related protein complex 4 subunit beta 1) This gene encodes a subunit of a heterotetrameric adapter-like complex 4 that is involved in targeting proteins from the trans-Golgi network to the endosomal-lysosomal system. Mutations in this gene are associated with cerebral palsy spastic quadriplegic type 5 (CPSQ5) disorder. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2011]
AP4B1-AS1 (HGNC:44114): (AP4B1 antisense RNA 1)

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 1-113898739-G-A is Pathogenic according to our data. Variant chr1-113898739-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 539527.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
AP4B1NM_001253852.3 linkc.1177C>T p.Arg393* stop_gained Exon 6 of 10 ENST00000369569.6 NP_001240781.1 Q9Y6B7-1A0A024R0J5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AP4B1ENST00000369569.6 linkc.1177C>T p.Arg393* stop_gained Exon 6 of 10 1 NM_001253852.3 ENSP00000358582.1 Q9Y6B7-1

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151968
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000725
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000147
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.00000405
AC:
1
AN:
247150
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000617
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1457520
Hom.:
0
Cov.:
32
AF XY:
0.00000414
AC XY:
3
AN XY:
725260
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49154
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111950
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000395
AC:
6
AN:
151968
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74222
show subpopulations
African (AFR)
AF:
0.0000725
AC:
3
AN:
41358
American (AMR)
AF:
0.0000655
AC:
1
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10542
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68010
Other (OTH)
AF:
0.000479
AC:
1
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000782
Hom.:
0
Bravo
AF:
0.0000340
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 47 Pathogenic:5
Apr 11, 2023
Genome-Nilou Lab
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Paris Brain Institute, Inserm - ICM
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 16, 2023
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. ClinVar contains an entry for this variant (Variation ID: 539527). This premature translational stop signal has been observed in individuals with hereditary spastic paraplegia (PMID: 32979048). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change creates a premature translational stop signal (p.Arg393*) in the AP4B1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AP4B1 are known to be pathogenic (PMID: 22290197, 24700674, 24781758). -

Nov 03, 2022
DASA
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1177C>T;p.(Arg393*) variant creates a premature translational stop signal in the AP4B1 gene. It is expected to result in an absent or disrupted protein product - PVS1. ClinVar contains an entry for this variant (ClinVar ID: 539527) - PS4_supporting. The variant is present at low allele frequencies population databases (rs374894037 – gnomAD 0.0003948%; ABraOM 0.000427 frequency - https://abraom.ib.usp.br/) - PM2_supporting. In summary, the currently available evidence indicates that the variant is pathogenic. -

Oct 11, 2019
HudsonAlpha Institute for Biotechnology, HudsonAlpha Institute for Biotechnology
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Spastic paraplegia Pathogenic:1
Oct 01, 2020
Yale Center for Mendelian Genomics, Yale University
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.43
CADD
Pathogenic
44
DANN
Uncertain
1.0
Eigen
Pathogenic
0.93
Eigen_PC
Pathogenic
0.78
FATHMM_MKL
Uncertain
0.91
D
PhyloP100
3.1
Vest4
0.41
GERP RS
4.5
Mutation Taster
=0/200
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: rs374894037; hg19: chr1-114441361; COSMIC: COSV108019675; COSMIC: COSV108019675; API