rs149705131

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5

The NM_001253852.3(AP4B1):c.617G>A(p.Arg206Gln) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000164 in 1,461,852 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R206G) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

AP4B1
NM_001253852.3 missense, splice_region

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:1

Conservation

PhyloP100: 7.11

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 links:

AP4B1-AS1 (HGNC:44114): (AP4B1 antisense RNA 1)

AP4B1-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-113901236-C-T is Pathogenic according to our data. Variant chr1-113901236-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 520727.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AP4B1	NM_001253852.3 link	c.617G>A	p.Arg206Gln	missense_variant, splice_region_variant	Exon 4 of 10	ENST00000369569.6	NP_001240781.1	Q9Y6B7-1A0A024R0J5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AP4B1	ENST00000369569.6 link	c.617G>A	p.Arg206Gln	missense_variant, splice_region_variant	Exon 4 of 10	1	NM_001253852.3	ENSP00000358582.1		Q9Y6B7-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251476

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135914

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 SAS exome

AF:

0.0000653

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000164

AC:

AN:

1461852

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727228

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 47

Pathogenic:1Uncertain:1

Jun 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 206 of the AP4B1 protein (p.Arg206Gln). This variant also falls at the last nucleotide of exon 5, which is part of the consensus splice site for this exon. This variant is present in population databases (rs149705131, gnomAD 0.006%). This missense change has been observed in individual(s) with hereditary spastic paraplegia (PMID: 31915823, 32979048). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 520727). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Jul 22, 2023

Neuberg Centre For Genomic Medicine, NCGM

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The missense/ splice region variant c.617G>Ap.Arg206Gln in AP4B1 gene has been reported previously in homozygous or compound heterozygous state in individuals affected with hereditary spastic paraplegia Ebrahimi-Fakhari et al., 2020. This variant is reported with the allele frequency of 0.002% in the gnomAD Exomes. This variant has been reported to the ClinVar database as Uncertain Significance / Likely Pathogenic. The amino acid Arg at position 206 is changed to a Gln changing protein sequence and it might alter its composition and physico-chemical properties. Multiple lines of computational evidence Polyphen-probably damaging, SIFT-damaging and Mutation Taster-disease causing predict a damaging effect on protein structure and function for this variant.This variant is predicted as damaging by SpliceAI Prediction. The reference amino acid p.Arg206Gln in AP4B1 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates .It has also been observed to segregate with disease in related individuals. For these reasons, this variant has been classified as Likely Pathogenic. -

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

- -

Inborn genetic diseases

Pathogenic:1

Jun 15, 2015

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:1

Nov 15, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Alters the last nucleotide of the exon and is predicted to destroy the splice donor site and result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25693842, 21620353, 23472171, 24700674, 26795593, 19559397, 23167973, 20972249, 29193663, 22290197, 24395635, 25552650, 31915823, 32979048) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.21

BayesDel_addAF

Uncertain

0.032

BayesDel_noAF

Uncertain

-0.010

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.34

T;T;T;T

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.95

.;D;D;D

M_CAP

Uncertain

0.085

MetaRNN

Uncertain

0.47

T;T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Uncertain

2.6

M;M;.;.

PrimateAI

Uncertain

0.64

PROVEAN

Uncertain

-3.0

D;D;D;D

REVEL

Benign

0.21

Sift

Uncertain

0.0040

D;D;D;D

Sift4G

Uncertain

0.014

D;D;.;.

Polyphen

0.77

P;P;.;.

Vest4

0.79

MVP

0.58

MPC

0.35

ClinPred

0.91

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.66

gMVP

0.57

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.52

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.52

Position offset: 0

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