7-94426472-C-T

Variant names:

• chr7-94426472-C-T
• rs377278762
• NM_000089.4:c.3047C>T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_000089.4(COL1A2):​c.3047C>T​(p.Pro1016Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,248 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1016H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: COL1A2 NM_000089.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.817
• Publications: 0 publications found

Genes affected

COL1A2 (HGNC:2198): (collagen type I alpha 2 chain) This gene encodes the pro-alpha2 chain of type I collagen whose triple helix comprises two alpha1 chains and one alpha2 chain. Type I is a fibril-forming collagen found in most connective tissues and is abundant in bone, cornea, dermis and tendon. Mutations in this gene are associated with osteogenesis imperfecta types I-IV, Ehlers-Danlos syndrome type VIIB, recessive Ehlers-Danlos syndrome Classical type, idiopathic osteoporosis, and atypical Marfan syndrome. Symptoms associated with mutations in this gene, however, tend to be less severe than mutations in the gene for the alpha1 chain of type I collagen (COL1A1) reflecting the different role of alpha2 chains in matrix integrity. Three transcripts, resulting from the use of alternate polyadenylation signals, have been identified for this gene. [provided by R. Dalgleish, Feb 2008]

COL1A2 Gene-Disease associations (from GenCC):

• Ehlers-Danlos syndrome, arthrochalasia type, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Illumina, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• osteogenesis imperfecta

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• osteogenesis imperfecta type 1

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• osteogenesis imperfecta type 2

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen
• osteogenesis imperfecta type 3

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• osteogenesis imperfecta type 4

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Ehlers-Danlos syndrome, arthrochalasia type

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
• Ehlers-Danlos syndrome, cardiac valvular type

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, ClinGen, PanelApp Australia, Orphanet, G2P
• combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen, Ambry Genetics
• Ehlers-Danlos/osteogenesis imperfecta syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• high bone mass osteogenesis imperfecta

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 uncertain in NM_000089.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the COL1A2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 437 curated pathogenic missense variants (we use a threshold of 10). The gene has 17 curated benign missense variants. Gene score misZ: 2.1491 (below the threshold of 3.09). Trascript score misZ: 3.5344 (above the threshold of 3.09). GenCC associations: The gene is linked to osteogenesis imperfecta, osteogenesis imperfecta type 1, osteogenesis imperfecta type 4, Ehlers-Danlos syndrome, cardiac valvular type, Ehlers-Danlos syndrome, arthrochalasia type, 2, combined osteogenesis imperfecta and Ehlers-Danlos syndrome 2, Ehlers-Danlos syndrome, arthrochalasia type, osteogenesis imperfecta type 3, osteogenesis imperfecta type 2, high bone mass osteogenesis imperfecta, Ehlers-Danlos/osteogenesis imperfecta syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.22931117).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL1A2	NM_000089.4	c.3047C>T	p.Pro1016Leu	missense_variant	Exon 46 of 52	ENST00000297268.11	NP_000080.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL1A2	ENST00000297268.11	c.3047C>T	p.Pro1016Leu	missense_variant	Exon 46 of 52	1	NM_000089.4	ENSP00000297268.6
COL1A2	ENST00000478215.1	n.606C>T		non_coding_transcript_exon_variant	Exon 4 of 4	3
COL1A2	ENST00000481570.5	n.3020C>T		non_coding_transcript_exon_variant	Exon 5 of 8	2
COL1A2	ENST00000488121.1	n.-38C>T		upstream_gene_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455248 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 722814

⚠️ 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: 33434

American (AMR) AF: 0.00 AC: 0 AN: 43962

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25914

East Asian (EAS) AF: 0.0000253 AC: 1 AN: 39514

South Asian (SAS) AF: 0.00 AC: 0 AN: 84088

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53000

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109406

Other (OTH) AF: 0.00 AC: 0 AN: 60170

⚠️ 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 v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.063
BayesDel_addAF	Uncertain	0.094	D
BayesDel_noAF	Benign	-0.10
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Benign	0.15	T;.
Eigen	Benign	-0.44
Eigen_PC	Benign	-0.32
FATHMM_MKL	Benign	0.47	N
LIST_S2	Uncertain	0.87	D;D
M_CAP	Benign	0.043	D
MetaRNN	Benign	0.23	T;T
MetaSVM	Uncertain	0.30	D
MutationAssessor	Uncertain	2.0	M;.
PhyloP100		0.82
PrimateAI	Benign	0.38	T
PROVEAN	Benign	-1.7	N;.
REVEL	Benign	0.25
Sift	Benign	0.11	T;.
Sift4G	Benign	0.24	T;T
Polyphen		0.020	B;.
Vest4		0.20
MutPred		0.29		Loss of methylation at K1014 (P = 0.0682);.;
MVP		0.59
MPC		0.22
ClinPred		0.46	T
GERP RS		2.8
Varity_R		0.061
gMVP		0.45
Mutation Taster		=94/6	polymorphism

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: rs377278762; hg19: chr7-94055784;