8-6936769-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001925.3(DEFA4):c.131T>C(p.Ile44Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,422 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DEFA4 NM_001925.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.134

Genes affected

DEFA4 (HGNC:2763): (defensin alpha 4) Defensins are a family of antimicrobial and cytotoxic peptides thought to be involved in host defense. They are abundant in the granules of neutrophils and also found in the epithelia of mucosal surfaces such as those of the intestine, respiratory tract, urinary tract, and vagina. Members of the defensin family are highly similar in protein sequence and distinguished by a conserved cysteine motif. Several alpha defensin genes are clustered on chromosome 8. This gene differs from other genes of this family by an extra 83-base segment that is apparently the result of a recent duplication within the coding region. The protein encoded by this gene, defensin, alpha 4, is found in the neutrophils; it exhibits corticostatic activity and inhibits corticotropin stimulated corticosterone production. [provided by RefSeq, Oct 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.888

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DEFA4	NM_001925.3	c.131T>C	p.Ile44Thr	missense_variant	2/3	ENST00000297435.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DEFA4	ENST00000297435.3	c.131T>C	p.Ile44Thr	missense_variant	2/3	1	NM_001925.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460422 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726330

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Feb 28, 2023

The c.131T>C (p.I44T) alteration is located in exon 2 (coding exon 1) of the DEFA4 gene. This alteration results from a T to C substitution at nucleotide position 131, causing the isoleucine (I) at amino acid position 44 to be replaced by a threonine (T). 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	Pathogenic	0.64
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.40
Cadd	Benign	17
Dann	Uncertain	0.98
DEOGEN2	Benign	0.061	T
Eigen	Benign	-0.63
Eigen_PC	Benign	-0.90
FATHMM_MKL	Benign	0.011	N
M_CAP	Benign	0.0026	T
MetaRNN	Pathogenic	0.89	D
MetaSVM	Benign	-0.99	T
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-2.8	D
REVEL	Benign	0.25
Sift	Uncertain	0.0060	D
Sift4G	Benign	0.096	T
Polyphen		0.98	D
Vest4		0.58
MutPred		0.78		Loss of stability (P = 0.0447);
MVP		0.28
MPC		0.0024
ClinPred		0.37	T
GERP RS		0.42
Varity_R		0.16
gMVP		0.15

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr8-6794291;