11-61364320-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_016464.5(TMEM138):c.-71G>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000765 in 1,581,000 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00011 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000073 (0 hom.)
• Consequence: TMEM138 NM_016464.5 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.75

Genes affected

TMEM138 (HGNC:26944): (transmembrane protein 138) This gene encodes a multi-pass transmembrane protein. Reduced expression of this gene in mouse fibroblasts causes short cilia and failure of ciliogenesis. Expression of this gene is tightly coordinated with expression of the neighboring gene TMEM216. Mutations in this gene are associated with the autosomal recessive neurodevelopmental disorder Joubert Syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2012]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.79).
• BS1: Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.0000728 (104/1428656) while in subpopulation MID AF= 0.00128 (6/4674). AF 95% confidence interval is 0.000559. There are 0 homozygotes in gnomad4_exome. There are 57 alleles in male gnomad4_exome subpopulation. Median coverage is 27. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM138	NM_016464.5	c.-71G>A		5_prime_UTR_variant	2/5	ENST00000278826.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM138	ENST00000278826.11	c.-71G>A		5_prime_UTR_variant	2/5	1	NM_016464.5	P1

Frequencies

GnomAD3 genomes AF: 0.000112 AC: 17 AN: 152226 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000262

Gnomad ASJ AF: 0.00115

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000132

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000728 AC: 104 AN: 1428656 Hom.: 0 Cov.: 27 AF XY: 0.0000804 AC XY: 57 AN XY: 708646

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000378

Gnomad4 ASJ exome AF: 0.000497

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000365

Gnomad4 FIN exome AF: 0.0000191

Gnomad4 NFE exome AF: 0.0000504

Gnomad4 OTH exome AF: 0.000187

GnomAD4 genome AF: 0.000112 AC: 17 AN: 152344 Hom.: 0 Cov.: 32 AF XY: 0.000107 AC XY: 8 AN XY: 74492

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000261

Gnomad4 ASJ AF: 0.00115

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000132

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000142 Hom.: 0

Bravo AF: 0.0000680

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Joubert syndrome 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
Cadd	Benign	13
Dann	Benign	0.57
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs199532763; hg19: chr11-61131792;