20-145640-C-T

Position:

• chr20-145640-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_030931.4(DEFB126):​c.284C>T​(p.Thr95Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,684 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: DEFB126 NM_030931.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.39

Genes affected

DEFB126 (HGNC:15900): (defensin beta 126) Defensins are cysteine-rich cationic polypeptides that are important in the immunologic response to invading microorganisms. The antimicrobial protein encoded by this gene is secreted and is a member of the beta defensin protein family. Beta defensin genes are found in several clusters throughout the genome, with this gene mapping to a cluster at 20p13. The encoded protein is highly similar to an epididymal-specific secretory protein (ESP13.2) from cynomolgus monkey. Mutation of this gene is associated with impaired sperm function. [provided by RefSeq, Nov 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.07191396).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DEFB126	NM_030931.4	c.284C>T	p.Thr95Ile	missense_variant	2/2	ENST00000382398.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DEFB126	ENST00000382398.4	c.284C>T	p.Thr95Ile	missense_variant	2/2	1	NM_030931.4	P1
DEFB126	ENST00000542572.1	n.189C>T		non_coding_transcript_exon_variant	3/3	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461684 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727144

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome Cov.: 32

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 24, 2023

The c.284C>T (p.T95I) alteration is located in exon 2 (coding exon 2) of the DEFB126 gene. This alteration results from a C to T substitution at nucleotide position 284, causing the threonine (T) at amino acid position 95 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Benign	-0.30	T
BayesDel_noAF	Benign	-0.67
CADD	Benign	0.051
DANN	Benign	0.44
DEOGEN2	Benign	0.020	T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.011	N
LIST_S2	Benign	0.31	T
M_CAP	Benign	0.0029	T
MetaRNN	Benign	0.072	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.34	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-1.4	N
REVEL	Benign	0.084
Sift	Benign	0.31	T
Sift4G	Benign	0.24	T
Polyphen		0.14	B
Vest4		0.12
MutPred		0.23		Loss of glycosylation at T95 (P = 8e-04);
MVP		0.067
MPC		0.11
ClinPred		0.22	T
GERP RS		-1.6
Varity_R		0.051
gMVP		0.12

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

Publications

LitVar

Other links and lift over

dbSNP: rs910503683; hg19: chr20-126281;