chrX-21868458-T-G

Variant names:

• chrX-21868458-T-G
• rs587777305
• NM_015884.4:c.671-9T>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP5 BP4

The NM_015884.4(MBTPS2):​c.671-9T>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 23)
• Consequence: MBTPS2 NM_015884.4 intron
• Scores: Splicing: ADA: 0.01712
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 0.993
• Publications: 6 publications found

Genes affected

MBTPS2 (HGNC:15455): (membrane bound transcription factor peptidase, site 2) This gene encodes a intramembrane zinc metalloprotease, which is essential in development. This protease functions in the signal protein activation involved in sterol control of transcription and the ER stress response. Mutations in this gene have been associated with ichthyosis follicularis with atrichia and photophobia (IFAP syndrome); IFAP syndrome has been quantitatively linked to a reduction in cholesterol homeostasis and ER stress response.[provided by RefSeq, Aug 2009]

MBTPS2 Gene-Disease associations (from GenCC):

• IFAP syndrome 1, with or without BRESHECK syndrome

  Inheritance: XL, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, Ambry Genetics
• keratosis follicularis spinulosa decalvans

  Inheritance: XL, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• Olmsted syndrome, X-linked

  Inheritance: XL Classification: STRONG, LIMITED Submitted by: G2P, Ambry Genetics
• osteogenesis imperfecta, type 19

  Inheritance: XL Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• mutilating palmoplantar keratoderma with periorificial keratotic plaques

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• osteogenesis imperfecta

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• BRESEK syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• keratosis follicularis spinulosa decalvans, X-linked

  Inheritance: XL Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-21868458-T-G is Pathogenic according to our data. Variant chrX-21868458-T-G is described in ClinVar as Pathogenic. ClinVar VariationId is 126904.Status of the report is no_assertion_criteria_provided, 0 stars.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.49). . Strength limited to SUPPORTING due to the PP5.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015884.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MBTPS2	NM_015884.4	MANE Select	c.671-9T>G		intron	N/A	NP_056968.1	O43462

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MBTPS2	ENST00000379484.10	TSL:1 MANE Select	c.671-9T>G		intron	N/A	ENSP00000368798.5	O43462
	MBTPS2	ENST00000365779.2	TSL:1	c.671-9T>G		intron	N/A	ENSP00000368796.1	B9ZVQ3
	MBTPS2	ENST00000860794.1		c.755-9T>G		intron	N/A	ENSP00000530853.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 21

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	IFAP syndrome 1, with or without BRESHECK syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.49
CADD	Benign	16
DANN	Benign	0.74
PhyloP100		0.99
Mutation Taster		=13/87	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.017
dbscSNV1_RF	Benign	0.28
SpliceAI score (max)		0.25		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.25		Position offset: 9

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

Other links and lift over

dbSNP: rs587777305; hg19: chrX-21886576;