chr8-38253642-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong

The NM_015214.3(DDHD2):c.1978G>C(p.Asp660His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000133 in 1,614,104 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

DDHD2
NM_015214.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:13

Conservation

PhyloP100: 9.90

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.921

PP5

Variant 8-38253642-G-C is Pathogenic according to our data. Variant chr8-38253642-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 39679.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr8-38253642-G-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DDHD2	NM_015214.3 link	c.1978G>C	p.Asp660His	missense_variant	Exon 16 of 18	ENST00000397166.7	NP_056029.2	O94830-1B3KPM6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DDHD2	ENST00000397166.7 link	c.1978G>C	p.Asp660His	missense_variant	Exon 16 of 18	2	NM_015214.3	ENSP00000380352.2		O94830-1

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152206

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000597

AC:

AN:

251466

Hom.:

AF XY:

0.0000662

AC XY:

AN XY:

135908

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000967

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000140

AC:

204

AN:

1461780

Hom.:

Cov.:

AF XY:

0.000117

AC XY:

AN XY:

727192

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.0000671

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:

0.000175

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000656

AC:

AN:

152324

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74486

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000140

Hom.:

Bravo

AF:

0.0000491

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000824

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000237

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:13

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 54

Pathogenic:8

Jan 01, 2016

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was classified as: Likely pathogenic. The following ACMG criteria were applied in classifying this variant: PS3,PM2,PP3,PP5. -

Dec 07, 2012

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

May 30, 2022

MGZ Medical Genetics Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Paris Brain Institute, Inserm - ICM

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Consultorio y Laboratorio de Neurogenética, Hospital JM Ramos Mejia

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 07, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: DDHD2 c.1978G>C (p.Asp660His) results in a non-conservative amino acid change located in the DDHD domain (IPR004177) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6e-05 in 251466 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1978G>C has been reported in the literature in multiple compound heterozygous and homozygous individuals affected with Hereditary Spastic Paraplegia 54, and the variant was shown to segregate with disease in related individuals (e.g., Schuurs-Hoeijmakers_2012, Citterio_2015). These data indicate that the variant is very likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 24337409, 23176823). Six ClinVar submitters (evaluation after 2014) have cited the variant, and all submitters classified the variant as pathogenic (n = 4) or likely pathogenic (n = 2). Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with histidine, which is basic and polar, at codon 660 of the DDHD2 protein (p.Asp660His). This variant is present in population databases (rs375168720, gnomAD 0.01%). This missense change has been observed in individual(s) with hereditary spastic paraplegia with thin corpus callosum (PMID: 23176823, 24337409, 24517879). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 39679). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt DDHD2 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects DDHD2 function (PMID: 25417924). For these reasons, this variant has been classified as Pathogenic. -

Apr 22, 2024

University of Science and Technology Houari Boumediene, Laboratory of Molecular and Cellular Biology (LBCM)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

This missense variant leads to the substitution of a highly conserved aspartic acid (found in 12 species) within the DDHD domain of the DDHD2 protein with histidine. Amino acid alignments were generated using Alamut® Visual v.2.15 software (Interactive Biosoftware, SOPHiA GENETICS). This variant is predicted to be disease-causing by standard in silico prediction tools (CADD, SIFT, PolyPhen-2, and MutationTaster). ClinVar contains an entry for this variant (Variation ID: 39679), it’s classified as pathogenic. This variant is not reported in the 1000 Genomes Project but is present at a low frequency in the gnomAD database [AF = 6.1e-5]. Complete co-segregation between the variant allele and the disease distribution was observed in the patients’ family. This variant was identified in the homozygous state in two affected siblings and was present in the heterozygous state in the unaffected parents. This variant is associated with the following publications: (PMID: 23176823, 24337409, 24517879, 30564185, 31302745, 25417924) -

not provided

Pathogenic:2

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 25, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies demonstrate a damaging effect; the D660H variant demonstrates a reduction in phospholipase A1 activity (Doi et al., 2014); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33084218, 25417924, 23176823, 24337409, 24517879, 31302745, 27535533) -

Inborn genetic diseases

Pathogenic:1

Aug 26, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1978G>C (p.D660H) alteration is located in exon 16 (coding exon 15) of the DDHD2 gene. This alteration results from a G to C substitution at nucleotide position 1978, causing the aspartic acid (D) at amino acid position 660 to be replaced by a histidine (H). Based on data from gnomAD, the C allele has an overall frequency of 0.006% (18/282874) total alleles studied. The highest observed frequency was 0.011% (14/129178) of European (non-Finnish) alleles. This variant has been identified in the homozygous state and/or in conjunction with other DDHD2 variant(s) in individual(s) with features consistent with DDHD2-related spastic paraplegia, and segregated with disease in a family/families; in at least one instance, the variants were identified in trans (Schuurs-Hoeijmakers, 2012; Citterio, 2014; Magariello, 2014; Nicita, 2019). This amino acid position is highly conserved in available vertebrate species. In multiple assays testing DDHD2 function, this variant showed functionally abnormal results (Doi, 2014; Chou, 2023). This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as pathogenic. -

Generalized epilepsy;C0028754:Obesity;C0557874:Global developmental delay

Pathogenic:1

Nov 28, 2016

Claritas Genomics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1978G>C (p.Asp660His) missense variant in the DDHD2 gene is previously reported in the literature and is expected to be causative of hereditary spastic paraplegia when present in the homozygous or compound heterozygous state. DDHD2 encodes a protein that makes up a subunit of the enzyme phospholipase A1 (PLA1). This variant has been reported in multiple affected individuals in the compound heterozygous or homozygous state and has been shown to segregate with disease in families. In vitro functional studies on cell lines with this variant demonstrated significantly reduced PLA1 activity when compared to that of wild type cell lines. This variant involves a highly conserved nucleotide and amino acid, and it is predicted to be damaging by PolyPhen-2, SIFT, and MutationTaster. Therefore, based on prior reports in the literature and functional evidence, this variant is classified as pathogenic. -

Hereditary spastic paraplegia

Pathogenic:1

May 17, 2019

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.39

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.79

D;D;.;D;D

Eigen

Uncertain

0.66

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

.;D;D;D;D

M_CAP

Uncertain

0.21

MetaRNN

Pathogenic

0.92

D;D;D;D;D

MetaSVM

Uncertain

0.24

MutationAssessor

Pathogenic

3.5

M;M;.;.;.

PrimateAI

Uncertain

0.77

PROVEAN

Pathogenic

-6.4

D;D;D;D;D

REVEL

Pathogenic

0.90

Sift

Pathogenic

0.0

D;D;D;D;D

Sift4G

Pathogenic

0.0

D;D;D;D;D

Polyphen

1.0

D;D;.;.;.

Vest4

0.92

MVP

0.95

MPC

0.69

ClinPred

0.96

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.98

gMVP

0.91

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over