chr7-100101744-CA-C

Variant summary

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

The NM_004722.4(AP4M1):​c.32delA​(p.Lys11ArgfsTer27) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000105 in 1,613,540 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

AP4M1
NM_004722.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3B:1

Conservation

PhyloP100: 4.29

Publications

1 publications found
Variant links:
Genes affected
AP4M1 (HGNC:574): (adaptor related protein complex 4 subunit mu 1) This gene encodes a subunit of the heterotetrameric AP-4 complex. The encoded protein belongs to the adaptor complexes medium subunits family. This AP-4 complex is involved in the recognition and sorting of cargo proteins with tyrosine-based motifs from the trans-golgi network to the endosomal-lysosomal system. [provided by RefSeq, Jul 2008]
MCM7 (HGNC:6950): (minichromosome maintenance complex component 7) The protein encoded by this gene is one of the highly conserved mini-chromosome maintenance proteins (MCM) that are essential for the initiation of eukaryotic genome replication. The hexameric protein complex formed by the MCM proteins is a key component of the pre-replication complex (pre_RC) and may be involved in the formation of replication forks and in the recruitment of other DNA replication related proteins. The MCM complex consisting of this protein and MCM2, 4 and 6 proteins possesses DNA helicase activity, and may act as a DNA unwinding enzyme. Cyclin D1-dependent kinase, CDK4, is found to associate with this protein, and may regulate the binding of this protein with the tumorsuppressor protein RB1/RB. Alternatively spliced transcript variants encoding distinct isoforms have been reported. [provided by RefSeq, Jul 2008]

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 does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 48 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-100101744-CA-C is Pathogenic according to our data. Variant chr7-100101744-CA-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 210211.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
AP4M1NM_004722.4 linkc.32delA p.Lys11ArgfsTer27 frameshift_variant Exon 1 of 15 ENST00000359593.9 NP_004713.2 O00189

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AP4M1ENST00000359593.9 linkc.32delA p.Lys11ArgfsTer27 frameshift_variant Exon 1 of 15 1 NM_004722.4 ENSP00000352603.4 O00189

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151986
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000319
AC:
8
AN:
250814
AF XY:
0.0000295
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000442
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461554
Hom.:
0
Cov.:
34
AF XY:
0.00000963
AC XY:
7
AN XY:
727100
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53390
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5688
European-Non Finnish (NFE)
AF:
0.00000989
AC:
11
AN:
1111834
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.00000658
AC:
1
AN:
151986
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41338
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10572
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67998
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
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:
0.00
Hom.:
0
Bravo
AF:
0.0000340

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3Benign:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 50 Pathogenic:2
Sep 13, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Lys11Argfs*27) in the AP4M1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in AP4M1 are known to be pathogenic (PMID: 24700674, 25496299, 25558065). This variant is present in population databases (rs770634405, gnomAD 0.009%). This premature translational stop signal has been observed in individual(s) with hereditary spastic paraplegia 50 (PMID: 32979048). ClinVar contains an entry for this variant (Variation ID: 210211). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -

Apr 29, 2014
Genetic Services Laboratory, University of Chicago
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
Feb 14, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported previously with a variant on the opposite allele (in trans) in a patient with a clinical diagnosis of AP-4-related hereditary spastic paraplegia (PMID: 32979048); however, no further clinical or segregation information was provided; 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; Observed with a likely pathogenic variant in an individual referred for genetic testing at GeneDx with features consistent with AP4M1-related spastic paraplegia and familial testing suggests the variants are likely present on opposite alleles (in trans); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 32979048) -

Intellectual disability Benign:1
Jan 01, 2019
Centre de Biologie Pathologie Génétique, Centre Hospitalier Universitaire de Lille
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
4.3
Mutation Taster
=1/199
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs797045249; hg19: chr7-99699367; API