rs397514754

chr16-75540130-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_001077418.3(TMEM231):c.815A>C(p.Gln272Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,482 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 Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TMEM231 NM_001077418.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.45

Genes affected

TMEM231 (HGNC:37234): (transmembrane protein 231) This gene encodes a transmembrane protein, which is a component of the B9 complex involved in the formation of the diffusion barrier between the cilia and plasma membrane. Mutations in this gene cause Joubert syndrome (JBTS). Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jan 2013]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98
• PP5: Variant 16-75540130-T-G is Pathogenic according to our data. Variant chr16-75540130-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 64620.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM231	NM_001077418.3	c.815A>C	p.Gln272Pro	missense_variant	7/7	ENST00000258173.11
TMEM231	NM_001077416.2	c.974A>C	p.Gln325Pro	missense_variant	6/6
TMEM231	NR_074083.2	n.981A>C		non_coding_transcript_exon_variant	7/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM231	ENST00000258173.11	c.815A>C	p.Gln272Pro	missense_variant	7/7	1	NM_001077418.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461482 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727014

Gnomad4 AFR exome AF: 0.0000299

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: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Meckel syndrome, type 11 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Mar 01, 2013

- -

Joubert syndrome and related disorders Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Sep 21, 2023

Variant summary: TMEM231 c.974A>C (p.Gln325Pro) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 247938 control chromosomes. c.974A>C has been reported at a homozygous state in at-least two individuals affected with MeckelGruber syndrome, both of whom was born from an Arabian consanguineous family (examples, Shaheen_2012, 2013, 2015, Maddirevula_2020, Shamseldin_2021). These data indicate that the variant is likely to be associated with Joubert Syndrome And Related Disorders. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 32552793, 26123494, 23349226, 27711071, 23169490). No submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.80
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
Cadd	Uncertain	26
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.71	D;.;D
Eigen	Uncertain	0.68
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.87	D;D;D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	0.057	D
MutationAssessor	Uncertain	2.7	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Pathogenic	-5.2	D;.;D
REVEL	Pathogenic	0.77
Sift	Pathogenic	0.0	D;.;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.94
MutPred		0.84		Loss of catalytic residue at Q272 (P = 0.0518);.;.;
MVP		0.77
MPC		0.045
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.96
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs397514754; hg19: chr16-75574028;