rs1555908820

Variant names:

• chrX-13768050-A-G
• rs1555908820
• NM_003611.3:c.2758-4A>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_003611.3(OFD1):​c.2758-4A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000945 in 1,057,988 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 24)
  • Exomes 𝑓: 9.5e-7 (0 hom. 0 hem.)
• Consequence: OFD1 NM_003611.3 splice_region, intron
• Scores: Splicing: ADA: 0.00005241
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.0200
• Publications: 0 publications found

Genes affected

OFD1 (HGNC:2567): (OFD1 centriole and centriolar satellite protein) This gene is located on the X chromosome and encodes a centrosomal protein. A knockout mouse model has been used to study the effect of mutations in this gene. The mouse gene is also located on the X chromosome, however, unlike the human gene it is not subject to X inactivation. Mutations in this gene are associated with oral-facial-digital syndrome type I and Simpson-Golabi-Behmel syndrome type 2. Many pseudogenes have been identified; a single pseudogene is found on chromosome 5 while as many as fifteen have been found on the Y chromosome. [provided by RefSeq, Aug 2016]

OFD1 Gene-Disease associations (from GenCC):

• ciliopathy

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• Joubert syndrome 10

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• orofaciodigital syndrome I

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• retinitis pigmentosa 23

  Inheritance: XL Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• primary ciliary dyskinesia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• orofaciodigital syndrome type 6

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Simpson-Golabi-Behmel syndrome type 2

  Inheritance: XL Classification: LIMITED Submitted by: G2P

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BP6: Variant X-13768050-A-G is Benign according to our data. Variant chrX-13768050-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 436104.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
OFD1	NM_003611.3	c.2758-4A>G		splice_region_variant, intron_variant	Intron 20 of 22	ENST00000340096.11	NP_003602.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
OFD1	ENST00000340096.11	c.2758-4A>G		splice_region_variant, intron_variant	Intron 20 of 22	1	NM_003611.3	ENSP00000344314.6

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome AF: 9.45e-7 AC: 1 AN: 1057988 Hom.: 0 Cov.: 25 AF XY: 0.00 AC XY: 0 AN XY: 330926

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

African (AFR) AF: 0.00 AC: 0 AN: 25681

American (AMR) AF: 0.00 AC: 0 AN: 35035

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19079

East Asian (EAS) AF: 0.00 AC: 0 AN: 29993

South Asian (SAS) AF: 0.00 AC: 0 AN: 52877

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4015

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 806105

Other (OTH) AF: 0.0000223 AC: 1 AN: 44791

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 24

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1

Feb 01, 2016

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Primary ciliary dyskinesia Benign:1

Jul 25, 2022

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	0.83
DANN	Benign	0.70
PhyloP100		0.020

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000052
dbscSNV1_RF	Benign	0.048
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: rs1555908820; hg19: chrX-13786169;