rs121917818

Positions:

• chr5-177607505-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_007255.3(B4GALT7):​c.617T>C​(p.Leu206Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,410 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: B4GALT7 NM_007255.3 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.35

Genes affected

B4GALT7 (HGNC:930): (beta-1,4-galactosyltransferase 7) This gene is a member of the beta-1,4-galactosyltransferase (beta4GalT) family. Family members encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose. Each beta4GalT member has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus which then remains uncleaved to function as a transmembrane anchor. The enzyme encoded by this gene attaches the first galactose in the common carbohydrate-protein linkage (GlcA-beta1,3-Gal-beta1,3-Gal-beta1,4-Xyl-beta1-O-Ser) found in proteoglycans. This enzyme differs from other beta4GalTs because it lacks the conserved Cys residues found in beta4GalT1-beta4GalT6 and it is located in cis-Golgi instead of trans-Golgi. Mutations in this gene have been associated with the progeroid form of Ehlers-Danlos syndrome. [provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a topological_domain Lumenal (size 275) in uniprot entity B4GT7_HUMAN there are 17 pathogenic changes around while only 7 benign (71%) in NM_007255.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 5-177607505-T-C is Pathogenic according to our data. Variant chr5-177607505-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 5612.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr5-177607505-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GALT7	NM_007255.3	c.617T>C	p.Leu206Pro	missense_variant	3/6	ENST00000029410.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GALT7	ENST00000029410.10	c.617T>C	p.Leu206Pro	missense_variant	3/6	1	NM_007255.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460410 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726598

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Ehlers-Danlos syndrome progeroid type Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Oct 08, 1999

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D
Eigen	Pathogenic	0.68
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.95	D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Benign	-0.30	T
MutationAssessor	Pathogenic	3.5	M
MutationTaster	Benign	1.0	A
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-5.2	D
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0020	D
Sift4G	Benign	0.063	T
Polyphen		0.86	P
Vest4		0.99
MutPred		0.95		Loss of catalytic residue at L206 (P = 0.0084);
MVP		0.53
MPC		0.82
ClinPred		0.99	D
GERP RS		5.3
Varity_R		0.99
gMVP		0.99

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: rs121917818; hg19: chr5-177034506;