chr9-109137563-C-G

Position:

• chr9-109137563-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_014334.4(FRRS1L):​c.774G>C​(p.Lys258Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,620 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FRRS1L NM_014334.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.31

Genes affected

FRRS1L (HGNC:1362): (ferric chelate reductase 1 like) This gene encodes a component of the outer-core of an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor protein in the brain. The encoded protein is thought to interact with inner-core components of the receptor, and play a role in the modulation of glutamate signaling. Mutations in this gene are associated with early infantile epileptic encephalopathy 37. [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2779347).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FRRS1L	NM_014334.4	c.774G>C	p.Lys258Asn	missense_variant	5/5	ENST00000561981.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FRRS1L	ENST00000561981.5	c.774G>C	p.Lys258Asn	missense_variant	5/5	1	NM_014334.4	P1
FRRS1L	ENST00000644747.1	c.*392G>C		3_prime_UTR_variant, NMD_transcript_variant	4/4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460620 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726664

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 37 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 22, 2022

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 575240). This variant has not been reported in the literature in individuals affected with FRRS1L-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 309 of the FRRS1L protein (p.Lys309Asn). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.40
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.044	T
Eigen	Uncertain	0.19
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.85	D
M_CAP	Benign	0.0039	T
MetaRNN	Benign	0.28	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.84	D
Sift4G	Uncertain	0.020	D
Polyphen		0.99	D
Vest4		0.23
MutPred		0.42		Loss of ubiquitination at K309 (P = 0.0103);
MVP		0.70
MPC		0.24
ClinPred		0.94	D
GERP RS		4.0
Varity_R		0.41
gMVP		0.77

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: rs1564227702; hg19: chr9-111899843;