19-46756272-C-T

Variant names:

• chr19-46756272-C-T
• rs77138370
• NM_024301.5:c.822C>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_024301.5(FKRP):​c.822C>T​(p.Ile274Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000133 in 1,508,780 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 7.4e-7 (0 hom.)
• Consequence: FKRP NM_024301.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.13
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• autosomal recessive limb-girdle muscular dystrophy type 2I

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics
• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, G2P, Ambry Genetics
• muscular dystrophy-dystroglycanopathy type B5

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae)
• myopathy caused by variation in FKRP

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• congenital muscular dystrophy with cerebellar involvement

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• congenital muscular dystrophy with intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• congenital muscular dystrophy without intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• muscle-eye-brain disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.56).
• BP7: Synonymous conserved (PhyloP=1.13 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FKRP	NM_024301.5	c.822C>T	p.Ile274Ile	synonymous_variant	Exon 4 of 4	ENST00000318584.10	NP_077277.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FKRP	ENST00000318584.10	c.822C>T	p.Ile274Ile	synonymous_variant	Exon 4 of 4	1	NM_024301.5	ENSP00000326570.4
FKRP	ENST00000391909.7	c.822C>T	p.Ile274Ile	synonymous_variant	Exon 4 of 4	2		ENSP00000375776.2
FKRP	ENST00000597339.5	n.247-5561C>T		intron_variant	Intron 3 of 3	5
FKRP	ENST00000600646.5	n.247+7607C>T		intron_variant	Intron 3 of 3	3

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151638 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000242

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 7.37e-7 AC: 1 AN: 1357142 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 667508

African (AFR) AF: 0.00 AC: 0 AN: 30640

American (AMR) AF: 0.00 AC: 0 AN: 32408

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23226

East Asian (EAS) AF: 0.00 AC: 0 AN: 35070

South Asian (SAS) AF: 0.00 AC: 0 AN: 75484

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 34806

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4678

European-Non Finnish (NFE) AF: 9.39e-7 AC: 1 AN: 1064444

Other (OTH) AF: 0.00 AC: 0 AN: 56386

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151638 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74024

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000242 AC: 1 AN: 41390

American (AMR) AF: 0.00 AC: 0 AN: 15232

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3456

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10498

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67734

Other (OTH) AF: 0.00 AC: 0 AN: 2086

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.56
CADD	Benign	10
DANN	Benign	0.83
PhyloP100		1.1

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

Other links and lift over

dbSNP: rs77138370; hg19: chr19-47259529;