11-61957454-TG-CC

Variant names:

• chr11-61957454-TG-CC
• NM_004183.4:c.704_705delTGinsCC
• BEST1 p.Val235Ala

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PS1 PM1 PM5 PP2 PP3

The NM_004183.4(BEST1):​c.704_705delTGinsCC​(p.Val235Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V235L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BEST1 NM_004183.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.82
• Publications: 0 publications found

Genes affected

BEST1 (HGNC:12703): (bestrophin 1) This gene encodes a member of the bestrophin gene family. This small gene family is characterized by proteins with a highly conserved N-terminus with four to six transmembrane domains. Bestrophins may form chloride ion channels or may regulate voltage-gated L-type calcium-ion channels. Bestrophins are generally believed to form calcium-activated chloride-ion channels in epithelial cells but they have also been shown to be highly permeable to bicarbonate ion transport in retinal tissue. Mutations in this gene are responsible for juvenile-onset vitelliform macular dystrophy (VMD2), also known as Best macular dystrophy, in addition to adult-onset vitelliform macular dystrophy (AVMD) and other retinopathies. Alternative splicing results in multiple variants encoding distinct isoforms.[provided by RefSeq, Nov 2008]

BEST1 Gene-Disease associations (from GenCC):

• autosomal dominant vitreoretinochoroidopathy

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• BEST1-related dominant retinopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• retinitis pigmentosa

  Inheritance: AD, AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P
• vitelliform macular dystrophy 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autosomal recessive bestrophinopathy

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• retinitis pigmentosa 50

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• adult-onset foveomacular vitelliform dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• MRCS syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• nanophthalmia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

LOC107984334 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PS1: Transcript NM_004183.4 (BEST1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 27 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_004183.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-61957454-T-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3249082.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 209 curated pathogenic missense variants (we use a threshold of 10). The gene has 23 curated benign missense variants. Gene score misZ: 0.61695 (below the threshold of 3.09). Trascript score misZ: 0.88358 (below the threshold of 3.09). GenCC associations: The gene is linked to autosomal recessive bestrophinopathy, BEST1-related dominant retinopathy, vitelliform macular dystrophy 2, adult-onset foveomacular vitelliform dystrophy, MRCS syndrome, autosomal dominant vitreoretinochoroidopathy, retinitis pigmentosa, retinitis pigmentosa 50, nanophthalmia.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004183.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BEST1	NM_004183.4	MANE Select	c.704_705delTGinsCC	p.Val235Ala	missense	N/A	NP_004174.1	O76090-1
	BEST1	NM_001440571.1		c.704_705delTGinsCC	p.Val235Ala	missense	N/A	NP_001427500.1
	BEST1	NM_001440572.1		c.704_705delTGinsCC	p.Val235Ala	missense	N/A	NP_001427501.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BEST1	ENST00000378043.9	TSL:1 MANE Select	c.704_705delTGinsCC	p.Val235Ala	missense	N/A	ENSP00000367282.4	O76090-1
	BEST1	ENST00000449131.6	TSL:1	c.524_525delTGinsCC	p.Val175Ala	missense	N/A	ENSP00000399709.2	O76090-3
	BEST1	ENST00000526988.1	TSL:2	c.386_387delTGinsCC	p.Val129Ala	missense	N/A	ENSP00000433195.1	B7Z1N8

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.8

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr11-61724926;