14-31066230-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001128126.3(AP4S1):c.34G>A(p.Gly12Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: AP4S1 NM_001128126.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.38

Genes affected

AP4S1 (HGNC:575): (adaptor related protein complex 4 subunit sigma 1) This gene encodes a member of the adaptor complexes small subunit protein family. These proteins are components of the heterotetrameric adaptor protein complexes, which play important roles in the secretory and endocytic pathways by mediating vesicle formation and sorting of integral membrane proteins. The encoded protein is the small subunit of adaptor protein complex-4, which is associated with both clathrin- and nonclathrin-coated vesicles. Mutations in this gene are associated with spastic quadriplegic cerebral palsy-6. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene, and a pseudogene of this gene is located on the long arm of chromosome 6. [provided by RefSeq, Dec 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.936

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AP4S1	NM_001128126.3	c.34G>A	p.Gly12Arg	missense_variant	2/6	ENST00000542754.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AP4S1	ENST00000542754.7	c.34G>A	p.Gly12Arg	missense_variant	2/6	1	NM_001128126.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Alfa AF: 0.000447 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spastic paraplegia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 21, 2022

This variant has not been reported in the literature in individuals affected with AP4S1-related conditions. 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. This variant is present in population databases (no rsID available, gnomAD 0.01%). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 12 of the AP4S1 protein (p.Gly12Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.49
Cadd	Pathogenic	31
Dann	Pathogenic	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;.;.;D;D;D;.;D;D;D
M_CAP	Benign	0.019	T
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.42	D
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-8.0	D;.;D;D;D;D;D;D;D;.
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;.;D;D;D;D;D;D;D;.
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	.;D;D;.;.;D;.;.;.;D
Vest4		0.98, 0.99, 0.98, 0.96, 0.96
MutPred		0.78		Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);Gain of solvent accessibility (P = 0.0171);
MVP		0.67
MPC		0.65
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.95
gMVP		0.76

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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

Other links and lift over

dbSNP: rs996367496; hg19: chr14-31535436;