1-197101927-G-C

Variant names:

• chr1-197101927-G-C
• rs769364943
• NM_018136.5:c.7324C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_018136.5(ASPM):​c.7324C>G​(p.Arg2442Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,460,884 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R2442Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: ASPM NM_018136.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.475
• Publications: 2 publications found

Genes affected

ASPM (HGNC:19048): (assembly factor for spindle microtubules) This gene is the human ortholog of the Drosophila melanogaster 'abnormal spindle' gene (asp), which is essential for normal mitotic spindle function in embryonic neuroblasts. Studies in mouse also suggest a role of this gene in mitotic spindle regulation, with a preferential role in regulating neurogenesis. Mutations in this gene are associated with microcephaly primary type 5. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, May 2011]

ASPM Gene-Disease associations (from GenCC):

• microcephaly 5, primary, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• autosomal recessive primary microcephaly

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ASPM	NM_018136.5	c.7324C>G	p.Arg2442Gly	missense_variant	Exon 18 of 28	ENST00000367409.9	NP_060606.3
ASPM	NM_001206846.2	c.4066-5763C>G		intron_variant	Intron 17 of 26		NP_001193775.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ASPM	ENST00000367409.9	c.7324C>G	p.Arg2442Gly	missense_variant	Exon 18 of 28	1	NM_018136.5	ENSP00000356379.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1460884 Hom.: 0 Cov.: 41 AF XY: 0.00000275 AC XY: 2 AN XY: 726754

African (AFR) AF: 0.00 AC: 0 AN: 33418

American (AMR) AF: 0.00 AC: 0 AN: 44594

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26100

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53328

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1111442

Other (OTH) AF: 0.00 AC: 0 AN: 60326

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000225 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Oct 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 2442 of the ASPM protein (p.Arg2442Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ASPM-related conditions. ClinVar contains an entry for this variant (Variation ID: 2190346). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt ASPM protein function with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.57	D
Eigen	Benign	0.19
Eigen_PC	Benign	-0.098
FATHMM_MKL	Benign	0.43	N
LIST_S2	Uncertain	0.87	D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.68	D
MetaSVM	Pathogenic	0.89	D
MutationAssessor	Pathogenic	4.3	H
PhyloP100		0.47
PrimateAI	Benign	0.32	T
PROVEAN	Uncertain	-3.8	D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.45
MVP		0.95
ClinPred		1.0	D
GERP RS		0.36
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.59
gMVP		0.29
Mutation Taster		=61/39	polymorphism

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

Other links and lift over

dbSNP: rs769364943; hg19: chr1-197071057;