12-56450177-G-A

Variant names:

• chr12-56450177-G-A
• rs886049689
• ENST00000648304.1:n.*1519C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The ENST00000648304.1(ENSG00000285528):​n.*1519C>T variant causes a non coding transcript exon 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ENSG00000285528 ENST00000648304.1 non_coding_transcript_exon
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.795
• Publications: 0 publications found

Genes affected

ENSG00000285528 (HGNC:):

MIP (HGNC:7103): (major intrinsic protein of lens fiber) Major intrinsic protein is a member of the water-transporting aquaporins as well as the original member of the MIP family of channel proteins. The function of the fiber cell membrane protein encoded by this gene is undetermined, yet this protein is speculated to play a role in intracellular communication. The MIP protein is expressed in the ocular lens and is required for correct lens function. This gene has been mapped among aquaporins AQP2, AQP5, and AQP6, in a potential gene cluster at 12q13. [provided by RefSeq, Jul 2008]

MIP Gene-Disease associations (from GenCC):

• cataract 15 multiple types

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• cerulean cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset lamellar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset nuclear cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset posterior polar cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• early-onset sutural cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• total early-onset cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MIP	NM_012064.4	c.*1103C>T		3_prime_UTR_variant	Exon 4 of 4	ENST00000652304.1	NP_036196.1
MIP	XM_011538354.2	c.*1103C>T		3_prime_UTR_variant	Exon 6 of 6		XP_011536656.1
MIP	XM_017019306.2	c.*1103C>T		3_prime_UTR_variant	Exon 4 of 4		XP_016874795.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ENSG00000285528	ENST00000648304.1	n.*1519C>T		non_coding_transcript_exon_variant	Exon 4 of 4			ENSP00000497190.1
MIP	ENST00000652304.1	c.*1103C>T		3_prime_UTR_variant	Exon 4 of 4		NM_012064.4	ENSP00000498622.1
ENSG00000285528	ENST00000648304.1	n.*1519C>T		3_prime_UTR_variant	Exon 4 of 4			ENSP00000497190.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cataract 15 multiple types Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	11
DANN	Benign	0.81
PhyloP100		0.80

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: rs886049689; hg19: chr12-56843961;