NM_004722.4:c.32delA

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_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

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]

AP4M1 links:

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]

MCM7 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 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 11 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 [Likely_pathogenic]. Clinvar id is 210211.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-100101744-CA-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AP4M1	NM_004722.4 link	c.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
AP4M1	ENST00000359593.9 link	c.32delA	p.Lys11ArgfsTer27	frameshift_variant	Exon 1 of 15	1	NM_004722.4	ENSP00000352603.4		O00189

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151986

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.0000319

AC:

AN:

250814

Hom.:

AF XY:

0.0000295

AC XY:

AN XY:

135782

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 SAS 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:

AN:

1461554

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727100

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000989

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151986

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74236

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

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

Apr 29, 2014

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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. -

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

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over