rs199422165

chr1-197104456-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_018136.5(ASPM):c.4795C>T(p.Arg1599Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,460,814 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: ASPM NM_018136.5 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5 O:1
• Conservation: PhyloP100: -0.247

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-197104456-G-A is Pathogenic according to our data. Variant chr1-197104456-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 21588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-197104456-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ASPM	NM_018136.5	c.4795C>T	p.Arg1599Ter	stop_gained	18/28	ENST00000367409.9
ASPM	NM_001206846.2	c.4066-8292C>T		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ASPM	ENST00000367409.9	c.4795C>T	p.Arg1599Ter	stop_gained	18/28	1	NM_018136.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000401 AC: 1 AN: 249524 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134944

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000545

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000958 AC: 14 AN: 1460814 Hom.: 0 Cov.: 38 AF XY: 0.00000826 AC XY: 6 AN XY: 726720

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000900

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000151

EpiCase AF: 0.0000546

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Microcephaly 5, primary, autosomal recessive Pathogenic:3 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Feb 08, 2013	- -
not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Apr 11, 2023	- -
Pathogenic, no assertion criteria provided	clinical testing	Service de Génétique Moléculaire, Hôpital Robert Debré	-	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	May 13, 2022	This sequence change creates a premature translational stop signal (p.Arg1599*) in the ASPM gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ASPM are known to be pathogenic (PMID: 19028728, 23611254). This variant is present in population databases (rs199422165, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with clinical features of ASPM-related conditions (PMID: 14574646). ClinVar contains an entry for this variant (Variation ID: 21588). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 28, 2018	The R1599X nonsense variant in the ASPM gene has been reported previously as a homozygous pathogenic variant in several families with microcephaly (Bond et al., 2013; Tan et al., 2014). This pathogenic variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. It is not observed at a significant frequency in large population cohorts (Lek et al., 2016). Therefore, R1599X is interpreted to be a pathogenic variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.31
Cadd	Pathogenic	26
Dann	Benign	0.84
Eigen	Benign	-0.72
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.018	N
MutationTaster	Benign	1.0	A;A;A
Vest4		0.36
GERP RS		-7.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs199422165; hg19: chr1-197073586; COSMIC: COSV99661261;