18-46569440-A-C

Position:

• chr18-46569440-A-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001384474.1(LOXHD1):​c.2244+2T>G variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: LOXHD1 NM_001384474.1 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 5.21

Genes affected

LOXHD1 (HGNC:26521): (lipoxygenase homology PLAT domains 1) This gene encodes a highly conserved protein consisting entirely of PLAT (polycystin/lipoxygenase/alpha-toxin) domains, thought to be involved in targeting proteins to the plasma membrane. Studies in mice show that this gene is expressed in the mechanosensory hair cells in the inner ear, and mutations in this gene lead to auditory defects, indicating that this gene is essential for normal hair cell function. Screening of human families segregating deafness identified a mutation in this gene which causes DFNB77, a progressive form of autosomal-recessive nonsyndromic hearing loss (ARNSHL). Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Mar 2010]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-46569440-A-C is Pathogenic according to our data. Variant chr18-46569440-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 505444.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LOXHD1	NM_001384474.1	c.2244+2T>G		splice_donor_variant		ENST00000642948.1	NP_001371403.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LOXHD1	ENST00000642948.1	c.2244+2T>G		splice_donor_variant			NM_001384474.1	ENSP00000496347	P1
LOXHD1	ENST00000441551.6	c.2244+2T>G		splice_donor_variant		5		ENSP00000387621
LOXHD1	ENST00000536736.5	c.2244+2T>G		splice_donor_variant		5		ENSP00000444586
LOXHD1	ENST00000335730.6	n.1557+2T>G		splice_donor_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 26, 2023

This sequence change affects a donor splice site in intron 16 of the LOXHD1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in LOXHD1 are known to be pathogenic (PMID: 19732867, 21465660, 25792669). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 505444). This variant has not been reported in the literature in individuals affected with LOXHD1-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Rare genetic deafness Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Nov 14, 2016

The c.2244+2T>G variant in LOXHD1 has not been previously reported in individual s with hearing loss or in large population studies. This variant occurs in the i nvariant region (+/- 1,2) of the splice consensus sequence and is predicted to c ause altered splicing leading to an abnormal or absent protein. Loss of functio n of the LOXHD1 gene is an established disease mechanism in autosomal recessive hearing loss. In summary, although additional studies are required to fully esta blish its clinical significance, this variant is likely pathogenic for autosomal recessive nonsyndromic hearing loss. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.030
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555681351; hg19: chr18-44149403;