2-32947529-G-A

Variant names:

• chr2-32947529-G-A
• rs959419457
• NM_206943.4:c.205G>A

Variant summary

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

The NM_206943.4(LTBP1):​c.205G>A​(p.Ala69Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000016 in 1,247,318 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. A69P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000016 (0 hom.)
• Consequence: LTBP1 NM_206943.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.421
• Publications: 0 publications found

Genes affected

LTBP1 (HGNC:6714): (latent transforming growth factor beta binding protein 1) The protein encoded by this gene belongs to the family of latent TGF-beta binding proteins (LTBPs). The secretion and activation of TGF-betas is regulated by their association with latency-associated proteins and with latent TGF-beta binding proteins. The product of this gene targets latent complexes of transforming growth factor beta to the extracellular matrix, where the latent cytokine is subsequently activated by several different mechanisms. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

LTBP1 Gene-Disease associations (from GenCC):

• cutis laxa, autosomal recessive, type 2E

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

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 (MetaRNN=0.060061008).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_206943.4. 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
	LTBP1	NM_206943.4	MANE Select	c.205G>A	p.Ala69Thr	missense	Exon 1 of 34	NP_996826.3	Q14766-1
	LTBP1	NM_001394905.1		c.205G>A	p.Ala69Thr	missense	Exon 1 of 34	NP_001381834.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LTBP1	ENST00000404816.7	TSL:5 MANE Select	c.205G>A	p.Ala69Thr	missense	Exon 1 of 34	ENSP00000386043.2	Q14766-1
	LTBP1	ENST00000929169.1		c.205G>A	p.Ala69Thr	missense	Exon 1 of 34	ENSP00000599228.1
	LTBP1	ENST00000954823.1		c.205G>A	p.Ala69Thr	missense	Exon 1 of 34	ENSP00000624882.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000160 AC: 2 AN: 1247318 Hom.: 0 Cov.: 34 AF XY: 0.00000326 AC XY: 2 AN XY: 612702

⚠️ 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: 24698

American (AMR) AF: 0.00 AC: 0 AN: 17518

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 20500

East Asian (EAS) AF: 0.00 AC: 0 AN: 26784

South Asian (SAS) AF: 0.0000321 AC: 2 AN: 62314

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 30966

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3542

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1010454

Other (OTH) AF: 0.00 AC: 0 AN: 50542

⚠️ 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
AlphaMissense	Benign	0.092
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	16
DANN	Benign	0.94
DEOGEN2	Benign	0.083	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.0052	N
LIST_S2	Benign	0.44	T
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.060	T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	0.0	N
PhyloP100		0.42
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	0.060	N
REVEL	Benign	0.087
Sift	Benign	0.72	T
Sift4G	Benign	0.53	T
Vest4		0.20
MutPred		0.23		Gain of glycosylation at A69 (P = 0.0033)
MVP		0.17
MPC		1.7
ClinPred		0.040	T
GERP RS		-0.071
Varity_R		0.044
gMVP		0.20
Mutation Taster		=96/4	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: rs959419457; hg19: chr2-33172596;