8-6621640-A-G

Position:

• chr8-6621640-A-G

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_Strong BP6 BS1 BS2

The NM_024596.5(MCPH1):​c.2401A>G​(p.Ser801Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00249 in 1,614,216 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0021 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0025 (7 hom.)
• Consequence: MCPH1 NM_024596.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:7
• Conservation: PhyloP100: 0.550

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 Benign. Variant got -13 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.007453501).
• BP6: Variant 8-6621640-A-G is Benign according to our data. Variant chr8-6621640-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 158856.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=2, Uncertain_significance=1}. Variant chr8-6621640-A-G is described in Lovd as [Likely_benign]. Variant chr8-6621640-A-G is described in Lovd as [Benign].
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00211 (322/152328) while in subpopulation NFE AF= 0.00297 (202/68024). AF 95% confidence interval is 0.00263. There are 0 homozygotes in gnomad4. There are 159 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
• BS2: High Homozygotes in GnomAdExome4 at 7 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MCPH1	NM_024596.5	c.2401A>G	p.Ser801Gly	missense_variant	13/14	ENST00000344683.10	NP_078872.3
MCPH1-AS1	NR_125386.1	n.230-5T>C		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MCPH1	ENST00000344683.10	c.2401A>G	p.Ser801Gly	missense_variant	13/14	1	NM_024596.5	ENSP00000342924	P1
MCPH1-AS1	ENST00000661193.1	n.1055-1416T>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00212 AC: 322 AN: 152210 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000603

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00847

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00297

Gnomad OTH AF: 0.000956

GnomAD3 exomes AF: 0.00255 AC: 635 AN: 249502 Hom.: 2 AF XY: 0.00233 AC XY: 316 AN XY: 135376

Gnomad AFR exome AF: 0.000517

Gnomad AMR exome AF: 0.000145

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00914

Gnomad NFE exome AF: 0.00360

Gnomad OTH exome AF: 0.00280

GnomAD4 exome AF: 0.00252 AC: 3691 AN: 1461888 Hom.: 7 Cov.: 51 AF XY: 0.00237 AC XY: 1724 AN XY: 727244

Gnomad4 AFR exome AF: 0.000508

Gnomad4 AMR exome AF: 0.000179

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00917

Gnomad4 NFE exome AF: 0.00277

Gnomad4 OTH exome AF: 0.00161

GnomAD4 genome AF: 0.00211 AC: 322 AN: 152328 Hom.: 0 Cov.: 33 AF XY: 0.00213 AC XY: 159 AN XY: 74488

Gnomad4 AFR AF: 0.000601

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00847

Gnomad4 NFE AF: 0.00297

Gnomad4 OTH AF: 0.000946

Alfa AF: 0.00244 Hom.: 2

Bravo AF: 0.00143

TwinsUK AF: 0.00162 AC: 6

ALSPAC AF: 0.00389 AC: 15

ESP6500AA AF: 0.000962 AC: 4

ESP6500EA AF: 0.00237 AC: 20

ExAC AF: 0.00290 AC: 351

EpiCase AF: 0.00202

EpiControl AF: 0.00249

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:7

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Benign:4

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 23, 2020	- -
Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Dec 01, 2022	MCPH1: BP4, BS2 -

not specified Benign:3

Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 02, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 19, 2016	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Microcephaly 1, primary, autosomal recessive Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.46	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	3.5
DANN	Benign	0.91
DEOGEN2	Benign	0.075	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.037	N
M_CAP	Benign	0.021	T
MetaRNN	Benign	0.0075	T
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	1.0	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-1.2	N
REVEL	Benign	0.15
Sift	Benign	0.40	T
Sift4G	Benign	0.30	T
Polyphen		0.0030	B
Vest4		0.098
MVP		0.64
ClinPred		0.0012	T
GERP RS		0.51
Varity_R		0.14
gMVP		0.21

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

Publications

LitVar

Other links and lift over

dbSNP: rs45540031; hg19: chr8-6479161;