chr6-55439499-C-A

Variant names:

• chr6-55439499-C-A
• rs773428478
• NM_001042406.2:c.856G>T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001042406.2(HMGCLL1):​c.856G>T​(p.Gly286Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: HMGCLL1 NM_001042406.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.89

Genes affected

HMGCLL1 (HGNC:21359): (3-hydroxy-3-methylglutaryl-CoA lyase like 1) Enables hydroxymethylglutaryl-CoA lyase activity. Involved in ketone body biosynthetic process. Located in several cellular components, including cytosol; endoplasmic reticulum; and perinuclear region of cytoplasm. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.958

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HMGCLL1	NM_001042406.2	c.856G>T	p.Gly286Cys	missense_variant	Exon 8 of 9	ENST00000274901.9	NP_001035865.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HMGCLL1	ENST00000274901.9	c.856G>T	p.Gly286Cys	missense_variant	Exon 8 of 9	1	NM_001042406.2	ENSP00000274901.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1460730 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726662

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Feb 22, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.946G>T (p.G316C) alteration is located in exon 9 (coding exon 9) of the HMGCLL1 gene. This alteration results from a G to T substitution at nucleotide position 946, causing the glycine (G) at amino acid position 316 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	.;D;D;D;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Pathogenic	0.69	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.4	.;H;.;.;.
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-8.2	D;D;D;D;D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;D;D;D;.
Vest4		0.86
MutPred		0.79		.;Loss of disorder (P = 0.0132);.;.;.;
MVP		0.76
MPC		0.18
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.91
gMVP		0.95

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: rs773428478; hg19: chr6-55304297;