chr1-235448220-CAAAAAAAA-C

Variant names:

• chr1-235448220-CAAAAAAAA-C
• rs59405398
• NM_152490.5:c.*1978_*1985delTTTTTTTT

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_152490.5(B3GALNT2):​c.*1978_*1985delTTTTTTTT variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000215 in 465,430 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 24)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: B3GALNT2 NM_152490.5 3_prime_UTR
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.65
• Publications: 0 publications found

Genes affected

B3GALNT2 (HGNC:28596): (beta-1,3-N-acetylgalactosaminyltransferase 2) This gene encodes a member of the glycosyltransferase 31 family. The encoded protein synthesizes GalNAc:beta-1,3GlcNAc, a novel carbohydrate structure, on N- and O-glycans. Alternatively spliced transcript variants that encode different isoforms have been described. [provided by RefSeq, Mar 2013]

TBCE (HGNC:11582): (tubulin folding cofactor E) Cofactor E is one of four proteins (cofactors A, D, E, and C) involved in the pathway leading to correctly folded beta-tubulin from folding intermediates. Cofactors A and D are believed to play a role in capturing and stabilizing beta-tubulin intermediates in a quasi-native confirmation. Cofactor E binds to the cofactor D/beta-tubulin complex; interaction with cofactor C then causes the release of beta-tubulin polypeptides that are committed to the native state. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

TBCE Gene-Disease associations (from GenCC):

• hypoparathyroidism-retardation-dysmorphism syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet, G2P
• early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• encephalopathy, progressive, with amyotrophy and optic atrophy

  Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: PanelApp Australia, ClinGen, G2P, Ambry Genetics
• autosomal recessive Kenny-Caffey syndrome

  Inheritance: AR Classification: MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet

ENSG00000285053 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_152490.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	B3GALNT2	NM_152490.5	MANE Select	c.*1978_*1985delTTTTTTTT		3_prime_UTR	Exon 12 of 12	NP_689703.1	Q8NCR0-1
	TBCE	NM_003193.5	MANE Select	c.1400-116_1400-109delAAAAAAAA		intron	N/A	NP_003184.1	Q15813-1
	TBCE	NM_001287801.2		c.1553-116_1553-109delAAAAAAAA		intron	N/A	NP_001274730.1	Q15813-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	B3GALNT2	ENST00000366600.8	TSL:1 MANE Select	c.*1978_*1985delTTTTTTTT		3_prime_UTR	Exon 12 of 12	ENSP00000355559.3	Q8NCR0-1
	TBCE	ENST00000642610.2	MANE Select	c.1400-116_1400-109delAAAAAAAA		intron	N/A	ENSP00000494796.1	Q15813-1
	ENSG00000285053	ENST00000647186.1		c.1400-116_1400-109delAAAAAAAA		intron	N/A	ENSP00000494775.1

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome AF: 0.00000215 AC: 1 AN: 465430 Hom.: 0 AF XY: 0.00000396 AC XY: 1 AN XY: 252260

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

African (AFR) AF: 0.00 AC: 0 AN: 11272

American (AMR) AF: 0.00 AC: 0 AN: 24292

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 15364

East Asian (EAS) AF: 0.00 AC: 0 AN: 28250

South Asian (SAS) AF: 0.00 AC: 0 AN: 52534

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 29518

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 2968

European-Non Finnish (NFE) AF: 0.00000362 AC: 1 AN: 276268

Other (OTH) AF: 0.00 AC: 0 AN: 24964

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 24

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.6

Splicing

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

Other links and lift over

dbSNP: rs59405398; hg19: chr1-235611535;