Genetic Variant HMBS:c.33+130_33+135delTTTTTT (chr11-119085172-CTTTTTT-C) – ACMG Classification: Benign (-8 pts)

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BA1

The NM_000190.4(HMBS):c.33+130_33+135delTTTTTT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0188 in 790,702 control chromosomes in the GnomAD database, including 13 homozygotes. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.0021 ( 2 hom., cov: 0)

Exomes 𝑓: 0.020 ( 11 hom. )

Consequence

HMBS
NM_000190.4 intron

Scores

Not classified

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.83

Publications

0 publications found

Variant links:

Genes affected

HMBS (HGNC:4982): (hydroxymethylbilane synthase) This gene encodes a member of the hydroxymethylbilane synthase superfamily. The encoded protein is the third enzyme of the heme biosynthetic pathway and catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane. Mutations in this gene are associated with the autosomal dominant disease acute intermittent porphyria. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

HMBS Gene-Disease associations (from GenCC):

acute intermittent porphyria
Inheritance: SD, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet

HMBS links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -8 ACMG points.

BA1

GnomAd4 highest subpopulation (SAS) allele frequency at 95% confidence interval = 0.0587 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HMBS	NM_000190.4 link	c.33+130_33+135delTTTTTT		intron_variant	Intron 1 of 13	ENST00000652429.1	NP_000181.2	P08397-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HMBS	ENST00000652429.1 link	c.33+107_33+112delTTTTTT		intron_variant	Intron 1 of 13		NM_000190.4	ENSP00000498786.1		P08397-1

Frequencies

GnomAD3 genomes

AF:

0.00208

AC:

139

AN:

66766

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000544

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000418

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.0200

Gnomad SAS

AF:

0.0701

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000193

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0204

AC:

14734

AN:

723900

Hom.:

AF XY:

0.0207

AC XY:

7391

AN XY:

357690

show subpopulations

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

African (AFR)

AF:

0.0284

AC:

516

AN:

18142

American (AMR)

AF:

0.0205

AC:

236

AN:

11528

Ashkenazi Jewish (ASJ)

AF:

0.0165

AC:

169

AN:

10212

East Asian (EAS)

AF:

0.0380

AC:

293

AN:

7704

South Asian (SAS)

AF:

0.0350

AC:

1707

AN:

48704

European-Finnish (FIN)

AF:

0.0121

AC:

135

AN:

11194

Middle Eastern (MID)

AF:

0.0222

AC:

AN:

1896

European-Non Finnish (NFE)

AF:

0.0188

AC:

11036

AN:

587282

Other (OTH)

AF:

0.0220

AC:

600

AN:

27238

⚠️ 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.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.337

Heterozygous variant carriers

853

1705

2558

3410

4263

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

490

980

1470

1960

2450

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00210

AC:

140

AN:

66802

Hom.:

Cov.:

AF XY:

0.00311

AC XY:

AN XY:

29536

show subpopulations

African (AFR)

AF:

0.000598

AC:

AN:

18400

American (AMR)

AF:

0.000417

AC:

AN:

4796

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

2142

East Asian (EAS)

AF:

0.0199

AC:

AN:

1404

South Asian (SAS)

AF:

0.0703

AC:

AN:

1308

European-Finnish (FIN)

AF:

0.00

AC:

AN:

1126

Middle Eastern (MID)

AF:

0.00

AC:

AN:

European-Non Finnish (NFE)

AF:

0.000193

AC:

AN:

36234

Other (OTH)

AF:

0.00

AC:

AN:

858

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

1.8

Mutation Taster

=100/0

polymorphism

(source)

Splicing

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

11-119085172-CTTTTTTTTTTTTTTTTTTTTTT-CTTTTTTTTTTTTTTTT

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over