rs1555530022

Variant names:

• chr16-79599591-CTCGGGGTTCAGCTGCTG-TGCA
• rs1555530022
• NM_005360.5:c.295_312delCAGCAGCTGAACCCCGAGinsTGCA

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PP2 PP5_Moderate

The NM_005360.5(MAF):​c.295_312delCAGCAGCTGAACCCCGAGinsTGCA​(p.Gln99CysfsTer272) variant causes a frameshift, 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 DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 30)
• Consequence: MAF NM_005360.5 frameshift, missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.79
• Publications: 0 publications found

Genes affected

MAF (HGNC:6776): (MAF bZIP transcription factor) The protein encoded by this gene is a DNA-binding, leucine zipper-containing transcription factor that acts as a homodimer or as a heterodimer. Depending on the binding site and binding partner, the encoded protein can be a transcriptional activator or repressor. This protein plays a role in the regulation of several cellular processes, including embryonic lens fiber cell development, increased T-cell susceptibility to apoptosis, and chondrocyte terminal differentiation. Defects in this gene are a cause of juvenile-onset pulverulent cataract as well as congenital cerulean cataract 4 (CCA4). Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2010]

MAF Gene-Disease associations (from GenCC):

• Ayme-Gripp syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• cataract 21 multiple types

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics
• cataract - microcornea syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cerulean cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• pulverulent cataract

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Fine-Lubinsky syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000278058 (HGNC:):

ACMG classification

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

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 22 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 1.1779 (below the threshold of 3.09). Trascript score misZ: -0.24854 (below the threshold of 3.09). GenCC associations: The gene is linked to cerulean cataract, Fine-Lubinsky syndrome, cataract 21 multiple types, Ayme-Gripp syndrome, pulverulent cataract, cataract - microcornea syndrome.
• PP5: Variant 16-79599591-CTCGGGGTTCAGCTGCTG-TGCA is Pathogenic according to our data. Variant chr16-79599591-CTCGGGGTTCAGCTGCTG-TGCA is described in ClinVar as Pathogenic. ClinVar VariationId is 541764.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MAF	NM_005360.5	c.295_312delCAGCAGCTGAACCCCGAGinsTGCA	p.Gln99CysfsTer272	frameshift_variant, missense_variant	Exon 1 of 2	ENST00000326043.5	NP_005351.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAF	ENST00000326043.5	c.295_312delCAGCAGCTGAACCCCGAGinsTGCA	p.Gln99CysfsTer272	frameshift_variant, missense_variant	Exon 1 of 2	1	NM_005360.5	ENSP00000327048.4

Frequencies

GnomAD3 genomes Cov.: 30

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

GnomAD4 genome Cov.: 30

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Ayme-Gripp syndrome;C1857768:Cataract 21 multiple types Pathogenic:1

Jul 26, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change results in a premature translational stop signal in the MAF gene (p.Leu101Argfs*63). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 305 amino acids of the MAF protein. This variant is not present in population databases (ExAC no frequency). This variant has been observed to segregate with clinical features of MAF-related cataracts in a family (Invitae). This variant disrupts the p.Arg294 amino acid residue in MAF. Other variant(s) that disrupt this residue have been observed in individuals with MAF-related conditions (PMID:24968223, 26694549, Invitae), suggesting that it is a clinically significant residue. As a result, variants that disrupt this residue are likely to be causative of disease. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.8

Splicing

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

Other links and lift over

dbSNP: rs1555530022; hg19: chr16-79633488;