rs879255519

Variant names:

• chr16-57751303-G-A
• rs879255519
• NM_005886.3:c.432+1G>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_005886.3(KATNB1):​c.432+1G>A variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KATNB1 NM_005886.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.11
• Publications: 0 publications found

Genes affected

KATNB1 (HGNC:6217): (katanin regulatory subunit B1) Microtubules, polymers of alpha and beta tubulin subunits, form the mitotic spindle of a dividing cell and help to organize membranous organelles during interphase. Katanin is a heterodimer that consists of a 60 kDa ATPase (p60 subunit A 1) and an 80 kDa accessory protein (p80 subunit B 1). The p60 subunit acts to sever and disassemble microtubules, while the p80 subunit targets the enzyme to the centrosome. Katanin is a member of the AAA family of ATPases. [provided by RefSeq, Jul 2008]

KATNB1 Gene-Disease associations (from GenCC):

• lissencephaly 6 with microcephaly

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: PanelApp Australia, Ambry Genetics, Labcorp Genetics (formerly Invitae), Illumina, G2P
• microlissencephaly

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.021341464 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.7, offset of 19, new splice context is: tcgGTgact. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-57751303-G-A is Pathogenic according to our data. Variant chr16-57751303-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 180641.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KATNB1	NM_005886.3	c.432+1G>A		splice_donor_variant, intron_variant	Intron 6 of 19	ENST00000379661.8	NP_005877.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KATNB1	ENST00000379661.8	c.432+1G>A		splice_donor_variant, intron_variant	Intron 6 of 19	5	NM_005886.3	ENSP00000368982.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Lissencephaly 6 with microcephaly Pathogenic:1

Dec 17, 2014

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		7.1
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.98		Position offset: -1

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

Other links and lift over

dbSNP: rs879255519; hg19: chr16-57785215;