15-40622574-C-A

Variant names:

• chr15-40622574-C-A
• NM_144508.5:c.2310C>A
• KNL1 p.Val770Val

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_144508.5(KNL1):​c.2310C>A​(p.Val770Val) variant causes a synonymous 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. V770V) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KNL1 NM_144508.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.569
• Publications: 0 publications found

Genes affected

KNL1 (HGNC:24054): (kinetochore scaffold 1) The protein encoded by this gene is a component of the multiprotein assembly that is required for creation of kinetochore-microtubule attachments and chromosome segregation. The encoded protein functions as a scaffold for proteins that influence the spindle assembly checkpoint during the eukaryotic cell cycle and it interacts with at least five different kinetochore proteins and two checkpoint kinases. In adults, this gene is predominantly expressed in normal testes, various cancer cell lines and primary tumors from other tissues and is ubiquitously expressed in fetal tissues. This gene was originally identified as a fusion partner with the mixed-lineage leukemia (MLL) gene in t(11;15)(q23;q14). Mutations in this gene cause autosomal recessive primary microcephaly-4 (MCPH4). Alternative splicing results in multiple transcript variants encoding different isoforms. Additional splice variants have been described but their biological validity has not been confirmed. [provided by RefSeq, Jan 2013]

KNL1 Gene-Disease associations (from GenCC):

• microcephaly 4, primary, autosomal recessive

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autosomal recessive primary microcephaly

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

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=-0.5).
• BP7: Synonymous conserved (PhyloP=0.569 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_144508.5. 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
	KNL1	NM_144508.5	MANE Select	c.2310C>A	p.Val770Val	synonymous	Exon 10 of 26	NP_653091.3	Q8NG31-2
	KNL1	NM_170589.5		c.2388C>A	p.Val796Val	synonymous	Exon 11 of 27	NP_733468.3	Q8NG31-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KNL1	ENST00000399668.7	TSL:1 MANE Select	c.2310C>A	p.Val770Val	synonymous	Exon 10 of 26	ENSP00000382576.3	Q8NG31-2
	KNL1	ENST00000346991.9	TSL:1	c.2388C>A	p.Val796Val	synonymous	Exon 11 of 27	ENSP00000335463.6	Q8NG31-1
	KNL1	ENST00000533001.1	TSL:1	n.2455C>A		non_coding_transcript_exon	Exon 10 of 10

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 46

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.50
CADD	Benign	2.5
DANN	Benign	0.49
PhyloP100		0.57

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr15-40914772;