rs1555738380

Positions:

• chr19-46755847-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_024301.5(FKRP):​c.397G>T​(p.Ala133Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: FKRP NM_024301.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.425

Genes affected

FKRP (HGNC:17997): (fukutin related protein) This gene encodes a protein which is targeted to the medial Golgi apparatus and is necessary for posttranslational modification of dystroglycan. Mutations in this gene have been associated with congenital muscular dystrophy, cognitive disability, and cerebellar cysts. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined. [provided by RefSeq, Oct 2008]

FKRP (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10648942).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FKRP	NM_024301.5	c.397G>T	p.Ala133Ser	missense_variant	4/4	ENST00000318584.10	NP_077277.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FKRP	ENST00000318584.10	c.397G>T	p.Ala133Ser	missense_variant	4/4	1	NM_024301.5	ENSP00000326570.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1340332 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 656208

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: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 29, 2017

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. 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 tolerated, but these predictions have not been confirmed by published functional studies. 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 variant has not been reported in the literature in individuals with a FKRP-related disease. This sequence change replaces alanine with serine at codon 133 of the FKRP protein (p.Ala133Ser). The alanine residue is moderately conserved and there is a moderate physicochemical difference between alanine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.022	T
BayesDel_noAF	Benign	-0.27
CADD	Benign	7.8
DANN	Benign	0.63
DEOGEN2	Benign	0.20	.;T;T;T
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.25	N
LIST_S2	Benign	0.80	T;.;T;T
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.11	T;T;T;T
MetaSVM	Uncertain	0.59	D
MutationAssessor	Benign	0.34	.;N;N;.
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	-0.39	.;N;N;.
REVEL	Uncertain	0.31
Sift	Benign	0.81	.;T;T;.
Sift4G	Benign	0.39	T;T;T;T
Polyphen		0.0080	.;B;B;.
Vest4		0.13, 0.065
MutPred		0.18		Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);
MVP		0.61
MPC		0.57
ClinPred		0.054	T
GERP RS		-6.6
Varity_R		0.13
gMVP		0.53

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: rs1555738380; hg19: chr19-47259104;