chr9-120419961-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_018249.6(CDK5RAP2):c.4005-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000143 in 1,611,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

CDK5RAP2
NM_018249.6 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 4.19

Publications

6 publications found

Variant links:

Genes affected

CDK5RAP2 (HGNC:18672): (CDK5 regulatory subunit associated protein 2) This gene encodes a regulator of CDK5 (cyclin-dependent kinase 5) activity. The protein encoded by this gene is localized to the centrosome and Golgi complex, interacts with CDK5R1 and pericentrin (PCNT), plays a role in centriole engagement and microtubule nucleation, and has been linked to primary microcephaly and Alzheimer's disease. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2013]

CDK5RAP2 Gene-Disease associations (from GenCC):

autosomal recessive primary microcephaly
Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
microcephaly 3, primary, autosomal recessive
Inheritance: AR Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
corpus callosum, agenesis of
Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

CDK5RAP2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.2, offset of -38, new splice context is: gtcctggcttgggattttAGcat. 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;

PP5

Variant 9-120419961-C-T is Pathogenic according to our data. Variant chr9-120419961-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 158146.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CDK5RAP2	NM_018249.6 link	c.4005-1G>A		splice_acceptor_variant, intron_variant	Intron 26 of 37	ENST00000349780.9	NP_060719.4	Q96SN8-1B3KVI2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CDK5RAP2	ENST00000349780.9 link	c.4005-1G>A		splice_acceptor_variant, intron_variant	Intron 26 of 37	1	NM_018249.6	ENSP00000343818.4		Q96SN8-1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152212

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000477

AC:

AN:

251470

AF XY:

0.0000368

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000967

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1459534

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

726204

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33414

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26110

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.00

AC:

AN:

86194

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000180

AC:

AN:

1109938

Other (OTH)

AF:

0.00

AC:

AN:

60300

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152330

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74486

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41578

American (AMR)

AF:

0.00

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000193

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2106

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00109982), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000296

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000824

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Microcephaly 3, primary, autosomal recessive

Pathogenic:4

Jun 26, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The CDK5RAP2 c.4005-1G>A variant (rs587783387, ClinVar Variation ID:158146) has been detected in the compound heterozygous state in multiple individuals affected with primary microcephaly (Dawidziuk 2021, Tan 2014). This variant is found in the general population with an overall allele frequency of 0.005% (12/251,470 alleles) in the Genome Aggregation Database (v2.1.1). This variant disrupts the canonical splice acceptor site of intron 26, which is likely to negatively impact gene function. Based on available information, this variant is considered to be pathogenic. References:Dawidziuk M et al. Exome Sequencing Reveals Novel Variants and Expands the Genetic Landscape for Congenital Microcephaly. Genes (Basel). 2021 Dec 18;12(12):2014. PMID: 34946966. Tan CA et al. The first case of CDK5RAP2-related primary microcephaly in a non-consanguineous patient identified by next generation sequencing. Brain Dev. 2014 Apr;36(4):351-5. PMID: 23726037. -

Apr 01, 2014

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Aug 15, 2013

Genetic Services Laboratory, University of Chicago

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Service de Génétique Moléculaire, Hôpital Robert Debré

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not provided

Pathogenic:1

Jan 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 26 of the CDK5RAP2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CDK5RAP2 are known to be pathogenic (PMID: 15793586, 20460369, 26436113). This variant is present in population databases (rs587783387, gnomAD 0.01%). Disruption of this splice site has been observed in individual(s) with CDK5RAP2-related conditions (PMID: 23726037). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 158146). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.48

BayesDel_noAF

Pathogenic

0.38

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Uncertain

0.87

PhyloP100

4.2

GERP RS

5.2

Mutation Taster

=1/99

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.86

SpliceAI score (max)

0.91

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.91

Position offset: -2

DS_AL_spliceai

0.90

Position offset: -1

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over