14-53046809-C-A

Variant names:

• chr14-53046809-C-A
• rs1882046965
• NM_001160148.2:c.2662G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001160148.2(DDHD1):​c.2662G>T​(p.Glu888*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000124 in 1,611,132 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 (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: DDHD1 NM_001160148.2 stop_gained
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 4.32
• Publications: 0 publications found

Genes affected

DDHD1 (HGNC:19714): (DDHD domain containing 1) This gene is a member of the intracellular phospholipase A1 gene family. The protein encoded by this gene preferentially hydrolyzes phosphatidic acid. It is a cytosolic protein with some mitochondrial localization, and is thought to be involved in the regulation of mitochondrial dynamics. Overexpression of this gene causes fragmentation of the tubular structures in mitochondria, while depletion of the gene results in mitochondrial tubule elongation. Deletion of this gene in male mice caused fertility defects, resulting from disruption in the organization of the mitochondria during spermiogenesis. In humans, mutations in this gene have been associated with hereditary spastic paraplegia (HSP), also known as Strumpell-Lorrain disease, or, familial spastic paraparesis (FSP). This inherited disorder is characterized by progressive weakness and spasticity of the legs. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Aug 2015]

DDHD1 Gene-Disease associations (from GenCC):

• hereditary spastic paraplegia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• hereditary spastic paraplegia 28

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet, Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0152 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DDHD1	NM_001160148.2	c.2662G>T	p.Glu888*	stop_gained	Exon 13 of 13	ENST00000673822.2	NP_001153620.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DDHD1	ENST00000673822.2	c.2662G>T	p.Glu888*	stop_gained	Exon 13 of 13		NM_001160148.2	ENSP00000500986.2

Frequencies

GnomAD3 genomes AF: 0.00000660 AC: 1 AN: 151572 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459464 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726062

African (AFR) AF: 0.00 AC: 0 AN: 33360

American (AMR) AF: 0.00 AC: 0 AN: 44464

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26066

East Asian (EAS) AF: 0.00 AC: 0 AN: 39506

South Asian (SAS) AF: 0.00 AC: 0 AN: 85962

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53348

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5750

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1110718

Other (OTH) AF: 0.00 AC: 0 AN: 60290

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151668 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74024

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41334

American (AMR) AF: 0.00 AC: 0 AN: 15232

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5164

South Asian (SAS) AF: 0.00 AC: 0 AN: 4798

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10396

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 288

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67964

Other (OTH) AF: 0.00 AC: 0 AN: 2110

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Spasticity Uncertain:1

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Institute of Human Genetics, University of Wuerzburg

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		4.3
Vest4		0.10
GERP RS		5.9
Mutation Taster		=29/171	disease causing

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

Other links and lift over

dbSNP: rs1882046965; hg19: chr14-53513527;