Breaking News
July 22, 2018 - Frequency of joint replacements halved in rheumatoid arthritis patients between 1997-2010
July 22, 2018 - QUT researcher highlights growing impact of non-prescription antibiotics supply in pharmacies
July 22, 2018 - UK health communication researcher seeks solutions for disposing leftover medicine
July 22, 2018 - Pfizer Initiates Pivotal Phase 3 Program for Investigational Hemophilia B Gene Therapy Fidanacogene Elaparvovec
July 22, 2018 - Mutation discovered to protect against Alzheimer’s disease in mice
July 22, 2018 - Researchers reveal how patients in urban areas develop multiple, long-term conditions
July 22, 2018 - Replacing conventional cancer treatment with complementary therapy linked to increased risk of death
July 22, 2018 - Study uncovers molecular key for delaying progression of multiple sclerosis
July 22, 2018 - Availability of athletic trainer in high school reduces injury rates in girls’ sports, shows study
July 22, 2018 - FDA Approves Krintafel (tafenoquine) for the Radical Cure of Plasmodium vivax Malaria
July 22, 2018 - Novel nuclear medicine probe will help assess new drugs for neurodegenerative diseases
July 22, 2018 - Physical activity even during exposure to air pollution can reduce risk of heart attack
July 22, 2018 - Scientists discover protein regulator of myelin production
July 22, 2018 - Sleep disturbances associated with higher dementia risk
July 22, 2018 - Scientists move one step further in developing eye drops to treat age-related macular degeneration
July 22, 2018 - Five-Year Stroke Rates Lower After PCI Versus CABG
July 21, 2018 - Alopecia areata – Genetics Home Reference
July 21, 2018 - Study identifies overdose risk factors in youth with substance use disorders
July 21, 2018 - Drug in clinical trials for Parkinson’s disease offers hope for treating heart failure
July 21, 2018 - Coupling free malaria tests with diagnosis-dependent vouchers can improve rational use of ACTs
July 21, 2018 - Sweetness depends on molecular interactions between specific sugars and water in saliva
July 21, 2018 - Muscle fitness is strongly associated with improved rate of ageing in the brain
July 21, 2018 - Resetting E-Prescriptions for Opioids Helps Curb Use: Study
July 21, 2018 - Overuse of antibiotics not what the doctor ordered
July 21, 2018 - Bundled-payment system did not lower costs for serious medical conditions, shows study
July 21, 2018 - Therapy dogs found to be effective in reducing ADHD symptoms in children
July 21, 2018 - Could rotating multiple therapists better treat PTSD patients?
July 21, 2018 - Binge drinking impairs working memory in adolescent brain
July 21, 2018 - Dying at home could be beneficial for terminally ill cancer patients and their relatives
July 21, 2018 - Researchers identify subtypes of retinal ganglion cells using single-cell RNA sequencing
July 21, 2018 - Study uncovers opportunities to reduce death by suicide among cancer patients
July 21, 2018 - Genetic sequencing reveals new clues to aggressiveness of prostate cancer
July 21, 2018 - BioSight Launches a Phase 2b Clinical Trial of BST-236 as a First-Line Treatment of Acute Myeloid Leukemia
July 21, 2018 - First major study comparing robotic to open surgery published in The Lancet
July 21, 2018 - ADHD medications may fail to improve cognition in healthy college students, study shows
July 21, 2018 - Intervention program that includes a personalized app could benefit teens with suicidal thoughts
July 21, 2018 - Researchers identify new compound that protects against neurodegeneration
July 21, 2018 - Gene therapy may hold potential to treat people with spinal cord injuries
July 21, 2018 - FDA Approves Nivestym (filgrastim-aafi), a Biosimilar to Neupogen
July 21, 2018 - Surgeons have substantial impact on genetic testing in breast cancer patients who need it
July 21, 2018 - Species diversity can have positive and negative impacts on disease transmission
July 21, 2018 - Genome research suggests presence of enteric fever in medieval Europe
July 21, 2018 - Risk of Sensory Deficits Drops With Rising Gestational Age
July 21, 2018 - Mum’s sleep matters—the effect of sleep on an unborn baby
July 21, 2018 - UC San Diego researchers awarded two grants for investigating stem cell-based therapies
July 21, 2018 - Cellular ‘garbage disposal’ may actually work on some of the proteins to neuronal development
July 21, 2018 - More Pregnant Women Having Heart Attacks
July 21, 2018 - Acne Breakouts | NIH News in Health
July 21, 2018 - Change health messaging to focus on potential impact to help stop the next pandemic
July 21, 2018 - Frailty associated with poor survival rates in young heart patients
July 21, 2018 - New discovery could save millions of lives from fatal fungal infections
July 21, 2018 - OBD presents latest data on the use of EpiSwitch™ in predicting patient response to immunotherapy and identifying lymphoma subtypes
July 21, 2018 - Childhood adversity increases susceptibility to addiction via immune response
July 21, 2018 - Scientists identify potential target for the treatment of binge eating
July 21, 2018 - Whole-brain LIPUS therapy improves cognitive dysfunction in mice simulating dementia, Alzheimer’s
July 21, 2018 - Digital media use raising risk of ADHD symptoms among the young
July 21, 2018 - Phase 3 study of tanezumab in patients with osteoarthritis pain meets all three co-primary endpoints
July 21, 2018 - Restoring mitochondrial function to reverse aging-related skin wrinkles, hair loss in mice
July 21, 2018 - SP PennTech introduces RW-500 rotary vial washer for biotech, pharmaceutical applications
July 21, 2018 - Researchers to study molecular mechanisms behind susceptibility of males to autism
July 21, 2018 - Using tendon transfer surgery to restore key functions in spinal cord injury patient
July 21, 2018 - Scientists create wearable device that measures cortisol in sweat
July 21, 2018 - Researchers study efficacy and safety of new treatment for OUD
July 21, 2018 - Fourth Published Clinical Trial Confirms Long-Term Safety of Niagen Supplementation at High Doses and Shows Potential for Improvement in Liver Health
July 21, 2018 - Study examines effects of a two-day intermittent calorie restriction diet for patients with type 2 diabetes
July 21, 2018 - Greening vacant urban land reduces feelings of depression for surrounding residents
July 21, 2018 - Parents say intense gun violence in PG-13 movies appropriate for teens 15 and older
July 21, 2018 - Collaborative study to assess effects of exercise training for cognitive deficits in MS
July 21, 2018 - FAU researchers find possible cause of Parkinson’s disease in the patients’ immune system
July 21, 2018 - Protective qualities of ‘good cholesterol’ reduce after menopause
July 21, 2018 - Researchers develop new way to uncover hidden breast cancer tumors
July 21, 2018 - FDA approves first drug for treatment of adult AML patients with specific genetic mutation
July 21, 2018 - Top AI companies join hands to discover novel drugs for DMD
July 21, 2018 - Ferring announces FDA approval of ZOMACTON for injection in four new pediatric indications
July 20, 2018 - Researchers design proteins that can self-assemble into complex structures
July 20, 2018 - AVITA Medical expands management team to support launch of RECELL device to treat burns
July 20, 2018 - FDA Approves Tibsovo (ivosidenib) for Relapsed or Refractory Acute Myeloid Leukemia with an IDH1 Mutation
July 20, 2018 - Developmental screening and surveillance rates remain low, new study suggests
July 20, 2018 - TGen opens tissue donation portal to advance DIPG research
July 20, 2018 - Health impact of highly processed summertime staples
Gene mutation causes chronic bad breath

Gene mutation causes chronic bad breath

image_pdfDownload PDFimage_print

For the first time, researchers have uncovered that bad breath can be caused by a genetic defect. A mutation in the gene SELENBP1 leads to the absence of the protein that converts the sulphur compound methanethiol. Researchers from Radboud University and Radboud university medical center have published these findings in Nature Genetics.

Bad breath (halitosis) is usually caused by bacteria in the oral cavity that produce sulphur compounds. Little is known about other causes of bad breath, but it has long been thought that it might also have a genetic cause. In the nineties, Dr. Albert Tangerman (Radboud university medical center, internal medicine) discovered a Dutch family with several members having bad breath.

Together with Professor of Inborn errors of Metabolism Ron Wevers, he looked for a cause. They came across sulphur compounds, including the foul-smelling methanethiol. This compound gives rise to a strong cabbage-like odour. “Methanethiol is produced in large amounts in the intestines, and can originate from food. We believed that the protein responsible for getting rid of methanethiol was defective in these patients”, says Wevers, “however, we could not find a lead for this in their metabolism. The process by which the body counteracts this compound was unknown. So at that point we were stuck.”

From bacterium to human

Wevers presented this problem at several conventions and as a result was contacted by families from Germany and Portugal with the same problem. In addition, a collaboration with Microbiology Professor Huub Op den Camp, a specialist in sulphur conversion in bacteria, was established. Together with researchers from University of Warwick, they recently discovered a protein in the bacterium Hyphomicrobium that converts methanethiol: methanethiol oxidase.

The bacterium feeds on contamination in sewage, including sulphur compounds like methanethiol, removing them from the water.

The researchers then looked to see whether the gene encoding the methanethiol oxidase protein in the bacteria was also present in humans. The human gene that corresponded most closely was SELENBP1. Huub Op den Camp: But the function of the corresponding human protein SELENBP1 was unknown. This also meant we did not know which compounds our body converts methanethiol into. The gene SELENBP1 is reported in the literature to be involved in tumour suppression. However, we immediately hypothesized that the absence of this protein could be the cause of bad breath in these patients.”

Widely distributed defect in metabolism

Wevers and Op den Camp investigated the breath, blood and urine of these patients, and found an increased amount of methanethiol and dimethyl sulphide. Wevers: “That was a direct clue that in these patients’ metabolism an error occurs, leading to the accumulation of four sulphur compounds, including methanethiol, in their blood. Methanethiol and dimethyl sulphide are extremely volatile and are thus easily exhaled via the lungs. Because we had now identified the human protein converting methanethiol, SELENBP1, we looked at these patients’ DNA. We found they all had mutations in the gene SELENBP1.”

Further research produced more evidence for this new discovery. For example, these patients’ skin cells had significantly lower levels of the protein and showed little or no enzyme activity. This same pattern was found in knock-out mice. This led to the conclusion that SELENBP1 is indeed a methanethiol oxidase and that mutations in this gene cause chronic bad breath. This mutation might be more common than we think: the researchers calculated that about 1 in 90,000 people carry the mutation. No cure is available for these patients. For the present, they can reduce bad breath only by dietary measures. Further research will focus on the development of a possible therapy, and on the role of compounds deriving from methanethiol in a healthy metabolism.


Explore further:
Intellectual disabilities caused by protein defect

More information:
Arjan Pol et al. Mutations in SELENBP1, encoding a novel human methanethiol oxidase, cause extraoral halitosis, Nature Genetics (2017). DOI: 10.1038/s41588-017-0006-7

Journal reference:
Nature Genetics

Provided by:
Radboud University

Tagged with:

About author

Related Articles