NM_031433.4:c.899-2A>G

Variant names:

• chr11-119344393-T-C
• rs1245503127
• NM_031433.4:c.899-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_031433.4(MFRP):​c.899-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000000684 in 1,461,008 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MFRP NM_031433.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 4.38
• Publications: 0 publications found

Genes affected

MFRP (HGNC:18121): (membrane frizzled-related protein) This gene encodes a member of the frizzled-related protein family. The encoded protein plays an important role in eye development and mutations in this gene have been associated with nanophthalmos, posterior microphthalmia, retinitis pigmentosa, foveoschisis, and optic disc drusen. The protein is encoded by a bicistronic transcript which also encodes C1q and tumor necrosis factor related protein 5 (C1QTNF5). [provided by RefSeq, Jun 2013]

C1QTNF5 (HGNC:14344): (C1q and TNF related 5) This gene encodes a member of a family of proteins that function as components of basement membranes and may play a role in cell adhesion. Mutations in this gene have been associated with late-onset retinal degeneration. The protein may be encoded by either a bicistronic transcript including sequence from the upstream membrane frizzled-related protein gene (MFRP), or by a monocistronic transcript expressed from an internal promoter. [provided by RefSeq, Jun 2013]

C1QTNF5 Gene-Disease associations (from GenCC):

• late-onset retinal degeneration

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.2, offset of 29, new splice context is: ggaatctgactggcctccAGggc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-119344393-T-C is Pathogenic according to our data. Variant chr11-119344393-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 488460.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_031433.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MFRP	NM_031433.4	MANE Select	c.899-2A>G		splice_acceptor intron	N/A	NP_113621.1
	C1QTNF5	NM_015645.5		c.-1738-2A>G		splice_acceptor intron	N/A	NP_056460.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MFRP	ENST00000619721.6	TSL:1 MANE Select	c.899-2A>G		splice_acceptor intron	N/A	ENSP00000481824.1
	MFRP	ENST00000360167.4	TSL:2	c.898+239A>G		intron	N/A	ENSP00000353291.4
	MFRP	ENST00000529147.2	TSL:5	n.*239A>G		downstream_gene	N/A

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461008 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726790

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44654

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86138

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53310

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111528

Other (OTH) AF: 0.00 AC: 0 AN: 60344

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Isolated microphthalmia 5 Pathogenic:1

Aug 03, 2017

Molecular Genetics Laboratory, BC Children's and BC Women's Hospitals

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Uncertain	0.97	D
PhyloP100		4.4
GERP RS		4.5
Mutation Taster		=9/91	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.88		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.88		Position offset: -2

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

Other links and lift over

dbSNP: rs1245503127; hg19: chr11-119215103;