8-6621453-GC-TT

Position:

• chr8-6621453-GC-TT

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_024596.5(MCPH1):​c.2215-1_2215delinsTT variant causes a splice acceptor, coding sequence change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MCPH1 NM_024596.5 splice_acceptor, coding_sequence
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.28

Genes affected

MCPH1 (HGNC:6954): (microcephalin 1) This gene encodes a DNA damage response protein. The encoded protein may play a role in G2/M checkpoint arrest via maintenance of inhibitory phosphorylation of cyclin-dependent kinase 1. Mutations in this gene have been associated with primary autosomal recessive microcephaly 1 and premature chromosome condensation syndrome. Alternatively spliced transcript variants have been described. [provided by RefSeq, Feb 2010]

MCPH1-AS1 (HGNC:51655): (MCPH1 antisense RNA 1)

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 6.2, offset of 31, new splice context is: cgagtgccacttgtctgcAGggc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MCPH1	NM_024596.5	c.2215-1_2215delinsTT		splice_acceptor_variant, coding_sequence_variant	13/14	ENST00000344683.10
MCPH1-AS1	NR_125386.1	n.411_412delinsAA		non_coding_transcript_exon_variant	3/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MCPH1	ENST00000344683.10	c.2215-1_2215delinsTT		splice_acceptor_variant, coding_sequence_variant	13/14	1	NM_024596.5	P1
MCPH1-AS1	ENST00000661193.1	n.1055-1230_1055-1229delinsAA		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 07, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant has not been reported in the literature in individuals affected with MCPH1-related conditions. Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This variant results in the deletion of part of exon 13 (c.2215-1_2215delinsTT) of the MCPH1 gene. However, it is currently unclear if variants that occur in this region of the gene cause disease. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr8-6478974;