A new syndrome caused by mutations in AHDC1

May 1, 2014, Baylor College of Medicine

A team of researchers led by Baylor College of Medicine have identified the gene underlying a newly recognized genetic syndrome that has symptoms of sleep apnea, delayed speech and hyptonia, or generalized upper body weakness.

The study published online today in the American Journal of Human Genetics.

The Baylor researchers first studied a patient from Australia with these symptoms who had been seen by many doctors and had multiple diagnostic tests, without any diagnosis.

Although there was no family history of the disease, the researchers performed DNA sequence analysis on the patient and her parents to determine if there was an underlying genetic cause for her symptoms.

The results showed damaging mutations had newly arisen in five in the patient when compared with the parents DNA sequence.

One gene was a candidate for causing the disease because similar mutations were never seen in healthy control individuals.

"This led us to ask if there were any other undiagnosed disease cases that had similar mutations in this gene," said Dr. Fan Xia, assistant professor of molecular and and in the Whole Genome Laboratory at Baylor and the first author on the report.

An examination of data from unsolved cases at Baylor's Whole Genome Laboratory revealed three such possibilities, Xia said.

The team then performed DNA sequencing on these patients and their parents.

"We found that these patients also had damaging mutations that had newly arisen in the same gene AHDC1," said Xia. "The independent occurrence of new mutations in each of these families is extremely strong evidence that this gene is the cause of this syndrome."

The are in the 'AT-Hook binding DNA motif Containing' gene, AHDC1.

"Little is known about this gene and the discovery of its link to this syndrome is an important advance towards analyzing its function," said Dr. Richard Gibbs, director of the Human Genome Sequencing Center at Baylor and the corresponding author on the report.

Checking the clinical records of the four patients showed an unrealized similarity between the symptoms of each patient. The DNA discovery had therefore brought together patients from Australia, Pennsylvania and two different cities in Texas.

"This study illustrates a remarkable confluence of advanced technical development, data sharing and detailed clinical studies," said Gibbs. "We have simultaneously provided answers for the affected families and advanced an important basic research question."

The researchers noted that the frequency of this syndrome is not yet known, but extrapolating from the Baylor Whole Genome Laboratory suggests that there could be hundreds of affected individuals worldwide.

Explore further: Applying math to biology: Software identifies disease-causing mutations in undiagnosed illnesses

Related Stories

Applying math to biology: Software identifies disease-causing mutations in undiagnosed illnesses

April 22, 2014
A computational tool developed at the University of Utah has successfully identified diseases with unknown gene mutations in three separate cases, U of U researchers and their colleagues report in a new study in The American ...

Sequencing studies help pinpoint gene in Prader-Willi syndrome

September 29, 2013
As so many genome studies do, this study published online in the journal Nature Genetics began with a single patient and his parents who were in search of a diagnosis.

Mutations in leukemia gene linked to new childhood growth disorder

March 9, 2014
Mutations in a gene associated with leukaemia cause a newly described condition that affects growth and intellectual development in children, new research reports.

Researchers discover new genetic brain disorder in humans

April 24, 2014
A newly identified genetic disorder associated with degeneration of the central and peripheral nervous systems in humans, along with the genetic cause, is reported in the April 24, 2014 issue of Cell.

Study discovers gene that causes devastating mitochondrial diseases

August 29, 2013
Researchers have identified a novel disease gene in which mutations cause rare but devastating genetic diseases known as mitochondrial disorders.

European epilepsy consortium identifies new gene for severe childhood epilepsy

January 22, 2014
A European consortium of epilepsy researchers has reported the discovery of a new gene involved in severe childhood epilepsy. Using a novel combination of technologies, including trio exome sequencing of patient/parental ...

Recommended for you

The surprising role of gene architecture in cell fate decisions

January 16, 2018
Scientists read the code of life—the genome—as a sequence of letters, but now researchers have also started exploring its three-dimensional organisation. In a paper published in Nature Genetics, an interdisciplinary research ...

How incurable mitochondrial diseases strike previously unaffected families

January 15, 2018
Researchers have shown for the first time how children can inherit a severe - potentially fatal - mitochondrial disease from a healthy mother. The study, led by researchers from the MRC Mitochondrial Biology Unit at the University ...

Genes that aid spinal cord healing in lamprey also present in humans

January 15, 2018
Many of the genes involved in natural repair of the injured spinal cord of the lamprey are also active in the repair of the peripheral nervous system in mammals, according to a study by a collaborative group of scientists ...

The coming of age of gene therapy: A review of the past and path forward

January 11, 2018
After three decades of hopes tempered by setbacks, gene therapy—the process of treating a disease by modifying a person's DNA—is no longer the future of medicine, but is part of the present-day clinical treatment toolkit. ...

Large-scale study to pinpoint genes linked to obesity

January 10, 2018
It's not just diet and physical activity; your genes also determine how easily you lose or gain weight. In a study published in the January issue of Nature Genetics, researchers at the Icahn School of Medicine at Mount Sinai ...

Identical twins can share more than identical genes

January 9, 2018
An international group of researchers has discovered a new phenomenon that occurs in identical twins: independent of their identical genes, they share an additional level of molecular similarity that influences their biological ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.