17-75827978-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_199242.3(UNC13D):c.3260G>A(p.Arg1087Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000361 in 1,605,908 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1087W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000037 (0 hom.)
• Consequence: UNC13D NM_199242.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -1.11

Genes affected

UNC13D (HGNC:23147): (unc-13 homolog D) This gene encodes a protein that is a member of the UNC13 family, containing similar domain structure as other family members but lacking an N-terminal phorbol ester-binding C1 domain present in other Munc13 proteins. The protein appears to play a role in vesicle maturation during exocytosis and is involved in regulation of cytolytic granules secretion. Mutations in this gene are associated with familial hemophagocytic lymphohistiocytosis type 3, a genetically heterogeneous, rare autosomal recessive disorder. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.036917657).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
UNC13D	NM_199242.3	c.3260G>A	p.Arg1087Gln	missense_variant	32/32	ENST00000207549.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
UNC13D	ENST00000207549.9	c.3260G>A	p.Arg1087Gln	missense_variant	32/32	1	NM_199242.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152220 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000524 AC: 12 AN: 228998 Hom.: 0 AF XY: 0.0000636 AC XY: 8 AN XY: 125778

Gnomad AFR exome AF: 0.0000743

Gnomad AMR exome AF: 0.0000298

Gnomad ASJ exome AF: 0.000313

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000696

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000371 AC: 54 AN: 1453688 Hom.: 0 Cov.: 31 AF XY: 0.0000387 AC XY: 28 AN XY: 722746

Gnomad4 AFR exome AF: 0.0000301

Gnomad4 AMR exome AF: 0.0000452

Gnomad4 ASJ exome AF: 0.000231

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000370

Gnomad4 OTH exome AF: 0.0000501

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152220 Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4 AN XY: 74354

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.000288

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000901 Hom.: 0

Bravo AF: 0.0000227

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ExAC AF: 0.0000582 AC: 7

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial hemophagocytic lymphohistiocytosis 3 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jul 17, 2022	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1087 of the UNC13D protein (p.Arg1087Gln). This variant is present in population databases (rs760766927, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with UNC13D-related conditions. ClinVar contains an entry for this variant (Variation ID: 325241). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.078
BayesDel_addAF	Benign	-0.37	T
BayesDel_noAF	Benign	-0.57
Cadd	Benign	0.058
Dann	Benign	0.94
DEOGEN2	Benign	0.068	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.048	N
LIST_S2	Benign	0.52	T
M_CAP	Benign	0.036	D
MetaRNN	Benign	0.037	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.6	L
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-0.15	N
REVEL	Benign	0.023
Sift	Benign	0.27	T
Sift4G	Benign	0.15	T
Polyphen		0.0010	B
Vest4		0.028
MutPred		0.27		Loss of MoRF binding (P = 0.0016);
MVP		0.49
MPC		0.11
ClinPred		0.037	T
GERP RS		-2.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.027
gMVP		0.39

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: rs760766927; hg19: chr17-73824059;