6-75138968-T-A

Variant names:

• chr6-75138968-T-A
• rs1332779
• NM_004370.6:c.4958-7A>T

Variant summary

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

The NM_004370.6(COL12A1):​c.4958-7A>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,596 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL12A1 NM_004370.6 splice_region, intron
• Scores: Splicing: ADA: 0.00001651
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0760
• Publications: 0 publications found

Genes affected

COL12A1 (HGNC:2188): (collagen type XII alpha 1 chain) This gene encodes the alpha chain of type XII collagen, a member of the FACIT (fibril-associated collagens with interrupted triple helices) collagen family. Type XII collagen is a homotrimer found in association with type I collagen, an association that is thought to modify the interactions between collagen I fibrils and the surrounding matrix. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

COL12A1 Gene-Disease associations (from GenCC):

• Bethlem myopathy 2

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• Bethlem myopathy 2

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Illumina, Genomics England PanelApp
• Ullrich congenital muscular dystrophy 2

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Bethlem myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Ullrich congenital muscular dystrophy

  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).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004370.6. 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
	COL12A1	NM_004370.6	MANE Select	c.4958-7A>T		splice_region intron	N/A	NP_004361.3
	COL12A1	NM_001424113.1		c.4958-7A>T		splice_region intron	N/A	NP_001411042.1
	COL12A1	NM_001424114.1		c.4958-7A>T		splice_region intron	N/A	NP_001411043.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL12A1	ENST00000322507.13	TSL:1 MANE Select	c.4958-7A>T		splice_region intron	N/A	ENSP00000325146.8	Q99715-1
	COL12A1	ENST00000345356.10	TSL:1	c.1466-7A>T		splice_region intron	N/A	ENSP00000305147.9	Q99715-2
	COL12A1	ENST00000483888.6	TSL:5	c.4958-7A>T		splice_region intron	N/A	ENSP00000421216.1	D6RGG3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460596 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726504

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

African (AFR) AF: 0.00 AC: 0 AN: 33422

American (AMR) AF: 0.00 AC: 0 AN: 44448

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26072

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 85850

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111602

Other (OTH) AF: 0.00 AC: 0 AN: 60360

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	2.0
DANN	Benign	0.47
PhyloP100		-0.076

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000017
dbscSNV1_RF	Benign	0.0
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: rs1332779; hg19: chr6-75848684;