rs1312739762

Positions:

• chr8-38253035-CT-C
• chr8-38253035-CT-CTT

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_015214.3(DDHD2):​c.1803delT​(p.Phe601fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DDHD2 NM_015214.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.573

Genes affected

DDHD2 (HGNC:29106): (DDHD domain containing 2) This gene encodes a phospholipase enzyme containing sterile-alpha-motif (SAM), WWE, and DDHD domains. This protein participates in membrane trafficking between the endoplastic reticulum and the Golgi body. Mutations in this gene can cause autosomal recessive spastic paraplegia 54. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2013]

DDHD2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-38253035-CT-C is Pathogenic according to our data. Variant chr8-38253035-CT-C is described in ClinVar as [Pathogenic]. Clinvar id is 540287.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr8-38253035-CT-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DDHD2	NM_015214.3	c.1803delT	p.Phe601fs	frameshift_variant	15/18	ENST00000397166.7	NP_056029.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DDHD2	ENST00000397166.7	c.1803delT	p.Phe601fs	frameshift_variant	15/18	2	NM_015214.3	ENSP00000380352.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 54 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 26, 2021

For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals with DDHD2-related conditions. ClinVar contains an entry for this variant (Variation ID: 540287). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Phe601Leufs*53) in the DDHD2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in DDHD2 are known to be pathogenic (PMID: 23176823, 23486545). -

Computational scores

Source: dbNSFP v4.3

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: rs1312739762; hg19: chr8-38110553;