chr9-92715177-T-G

Position:

• chr9-92715177-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001003800.2(BICD2):​c.2545A>C​(p.Lys849Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000069 in 1,449,368 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. K849N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: BICD2 NM_001003800.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.19

Genes affected

BICD2 (HGNC:17208): (BICD cargo adaptor 2) This gene is one of two human homologs of Drosophila bicaudal-D and a member of the Bicoid family. It has been implicated in dynein-mediated, minus end-directed motility along microtubules. It has also been reported to be a phosphorylation target of NIMA related kinase 8. Two alternative splice variants have been described. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), BICD2. . Gene score misZ 2.205 (greater than the threshold 3.09). Trascript score misZ 3.1082 (greater than threshold 3.09). GenCC has associacion of gene with autosomal dominant childhood-onset proximal spinal muscular atrophy with contractures.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BICD2	NM_001003800.2	c.2545A>C	p.Lys849Gln	missense_variant	7/7	ENST00000356884.11
BICD2	NM_015250.4	c.2469+76A>C		intron_variant
BICD2	XM_017014551.2	c.2550+76A>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BICD2	ENST00000356884.11	c.2545A>C	p.Lys849Gln	missense_variant	7/7	1	NM_001003800.2	A2
BICD2	ENST00000375512.3	c.2469+76A>C		intron_variant		1		P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.90e-7 AC: 1 AN: 1449368 Hom.: 0 Cov.: 32 AF XY: 0.00000139 AC XY: 1 AN XY: 718910

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.06e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 10, 2023

The c.2545A>C (p.K849Q) alteration is located in exon 7 (coding exon 7) of the BICD2 gene. This alteration results from a A to C substitution at nucleotide position 2545, causing the lysine (K) at amino acid position 849 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Autosomal dominant childhood-onset proximal spinal muscular atrophy with contractures Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 20, 2023

This sequence change replaces lysine, which is basic and polar, with glutamine, which is neutral and polar, at codon 849 of the BICD2 protein (p.Lys849Gln). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BICD2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1497175). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BICD2 protein function. 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
BayesDel_addAF	Benign	-0.060	T
BayesDel_noAF	Benign	-0.32
CADD	Pathogenic	26
DANN	Uncertain	1.0
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.83	T
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.60	D
MetaSVM	Benign	-0.57	T
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-0.25	N
REVEL	Benign	0.16
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.99	D
Vest4		0.53
MutPred		0.34		Loss of methylation at K849 (P = 0.0025);
MVP		0.79
MPC		1.5
ClinPred		0.98	D
GERP RS		5.3
gMVP		0.32

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: rs1412613776; hg19: chr9-95477459;