18-11689757-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_182978.4(GNAL):c.194G>A(p.Arg65Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,512,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 10/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R65W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: GNAL NM_182978.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.475

Genes affected

GNAL (HGNC:4388): (G protein subunit alpha L) This gene encodes a stimulatory G protein alpha subunit which mediates odorant signaling in the olfactory epithelium. This protein couples dopamine type 1 receptors and adenosine A2A receptors and is widely expressed in the central nervous system. Mutations in this gene have been associated with dystonia 25 and this gene is located in a susceptibility region for bipolar disorder and schizophrenia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2013]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.1774503).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GNAL	NM_182978.4	c.194G>A	p.Arg65Gln	missense_variant	1/12	ENST00000334049.11
GNAL	XM_006722324.4	c.194G>A	p.Arg65Gln	missense_variant	1/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GNAL	ENST00000334049.11	c.194G>A	p.Arg65Gln	missense_variant	1/12	1	NM_182978.4
GNAL	ENST00000585590.1	n.68G>A		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151982 Hom.: 0 Cov.: 33

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

GnomAD4 exome AF: 0.0000118 AC: 16 AN: 1360216 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 9 AN XY: 671558

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000324

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000141

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151982 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74230

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: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dystonic disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 24, 2018

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 output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with GNAL-related disease. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This sequence change replaces arginine with glutamine at codon 65 of the GNAL protein (p.Arg65Gln). The arginine residue is weakly conserved and there is a small physicochemical difference between arginine and glutamine. The GNAL gene has multiple clinically relevant transcripts. The p.Arg65Gln variant occurs in the alternate transcript NM_182978.3, which corresponds to position c.-62052G>A in NM_001142339.2, the primary transcript listed in the Methods. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.51
Cadd	Benign	11
Dann	Uncertain	0.99
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.012	N
LIST_S2	Benign	0.57	T
M_CAP	Pathogenic	0.82	D
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-0.69	T
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-0.060	N
REVEL	Benign	0.074
Sift	Benign	0.073	T
Sift4G	Benign	0.46	T
Vest4		0.059
MutPred		0.22		Loss of MoRF binding (P = 0.0148);
MVP		0.59
MPC		1.5
ClinPred		0.21	T
GERP RS		0.48
gMVP		0.22

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1005314490; hg19: chr18-11689756;