In this family with 4 children with autism, genetic mapping and whole-exome sequencing identified a mutation in SYNE1, a gene that's known but never before associated with autism.
Autism clearly runs in some families, yet few inherited genetic causes have been found. A major reason is that these causes are so varied that it’s hard to find enough people with a given mutation to establish a clear pattern. Now, three large Middle Eastern families with autism spectrum disorders (ASDs) have led the way to a few more mutations, potentially broadening the number of genetic tests available to families.
What’s fascinating is that the mutations, described earlier this week in Neuron, affect genes known to cause severe, often lethal genetic syndromes. Milder mutations in the same genes, found through genomic sequencing, primarily cause autism.
Researchers Tim Yu, MD, PhD, Maria Chahrour, PhD, and senior investigator Christopher Walsh, MD, PhD, of Boston Children’s Hospital, started with three large families that had two or more children with an ASD, in which the parents were first cousins. Cousin marriages are a common tradition in the Middle East that greatly facilitates the identification of inherited mutations—as does large family size. Full story »
A new spinoff business will make large-scale genomic diagnostics a reality in medical practice (Image: Rosendahl)
Genomic sequencing and molecular diagnostics are becoming a global business. At the recent American Society of Human Genetics meeting, dazzling technologies for reading genetic code were on display—promising faster, cheaper, sleeker.
Nevertheless, it’s become clear that the ability to determine someone’s DNA or RNA sequence doesn’t automatically translate into useful diagnostics or even actionable information. In fact, the findings are often confusing and hard to interpret, even by physicians.
That’s where academic-industry partnerships can flourish—tapping the deep expertise of medical research centers to bring clinical meaning to sequencing findings. Yesterday, Boston Children’s Hospital and Life Technologies Corp. announced a new venture with a great list of ingredients: fast, accurate, scalable sequencing technology—Life’s Ion Proton® Sequencer—but also research and clinical experience in rare and genetic diseases, bioinformatics expertise to handle the big data, and the medical and counseling expertise to create meaning from the results. Full story »
Mice with the mutation causing Rett syndrome (middle panel) have an excess of inhibitory connections as compared with normal mice (left panel) and mutated mice reared with no visual stimulation (right panel). Inhibitory connections were also reduced by manipulating the NMDA receptor, restoring a more normal balance of inhibition/excitation.
Research just published in Neuron offers some interesting clues about Rett syndrome, a tragic disease that causes initially healthy girls to lose their ability to speak and to develop motor and respiratory problems. Working with a mouse model, the Boston Children’s Hospital lab of Michela Fagiolini, PhD, explored how the causative mutations, affecting the MECP2 gene, disrupt brain circuitry and function. The team found that the circuit damage can be undone by targeting the NMDA receptor, tipping the brain toward the right balance of inhibition and excitation. They’re now exploring possible pharmaceutical approaches.
The study also suggests that changes in the visual system are a tip-off to what’s going on in the brain as a whole. Full story »
Agustín Cáceres, once a virtual "bubble boy," is no longer on infectious disease precautions.
For the Cáceres family of Argentina, it’s a joyous holiday homecoming. Agustín, who received gene therapy at 5½ months of age, journeyed with his family to Boston for a check-up and got a clean bill of health.
Agustín was born with the rare immune-deficiency disorder SCID-X1. More popularly known as “bubble boy” disease, it left him defenseless against infections, unable to make enough T-cells to fight them off. His baptism was the only time his family could come near him, all wearing masks, gloves and gowns. His infancy was spent in isolation with his mother.
Now, at age 2½, Agustín has been cleared to go to nursery school, ride a bus and attend large family gatherings without fear of contracting a life-threatening infection. When we caught up with him, he was chasing and tumbling with his older brother Jeremías while waiting to bid farewell to his care team. Full story »
A “heat map” for autism gene expression (click to enlarge). Each row represents one of the 55 genes differently expressed in ASD patients vs. controls; columns show expression profiles for each of the 99 subjects. Genes in red have relatively increased gene activity; green, reduced activity. The bars along the bottom show how ASD patients vs. controls are distributed; overall, the ASD group has more genes over-expressed, while the control group has more down-regulated. The brackets at left connect genes that tend to be expressed together, while those along the top link individuals with similar gene expression patterns.
Though autism can respond well to early behavioral interventions, it’s typically not diagnosed in the U.S. until around age 5, when these interventions are less effective. Autism is diagnosed based on a child’s behaviors and language, which take time to develop to the point where clinicians can reliably assess them. What’s really needed is a fast, objective test when a child is much younger, before symptoms even show up.
In the past decade, researchers have chipped away at the problem, linking more than a dozen genetic mutations to autism—from small DNA “spelling” changes to lost or extra copies of a gene or genes (known as copy number variants) to wholesale chromosome abnormalities. Tests have been created, such as the chromosomal microarray test. But together, the known mutations account for, at best, 1 in 5 autism cases among tested patients. Full story »
An intestinal crypt enlarged by runaway tissue regeneration. (Courtesy Evan Barry)
We now know a lot about how the process of tissue regeneration gets started, and how to coax that process along to make repairs. But we know little about how to turn regeneration off, which is essential for keeping an organ at a normal size once the repair is complete. Finding that “off” switch may also be the key to halting growth of another kind: cancer.
Along with many other cancer researchers, Fernando Camargo, PhD, a researcher in the Boston Children’s Hospital Stem Cell Program, is hotly focused on a pathway called Hippo that’s known to regulate organ size. One member of this pathway, known as the “yes-associated protein” or YAP, has been found to say “yes” to growth so vigorously that activating it in mice makes the liver quadruple in size, as Camargo showed in 2007. YAP is also thought to be an oncogene, and has become a popular target in liver, ovarian and other cancers.
But Camargo, research fellow Evan Barry, PhD, and their colleagues recently found that saying “no” to YAP might not always be a good idea. Full story »
The Complex Care Service makes morning rounds. (L-R: CCS attending physician Melinda Morin, MD; pediatric resident Grant Rowe, MD, PhD; Tracy Allen, nurse practioner, CCS; Kristin Buxton, nurse practitioner, baclofen pump program.)
This is the second post of a two-part series on children with complex medical needs. (Read the first post.) Details on some patients have been changed for privacy reasons.
Led by attending physican Mindy Morin, MD, MBA, the Complex Care Service team starts down the 9th floor hall at Boston Children’s Hospital, pushing a cart carrying a computer and folders full of paperwork. They’ve just spent about an hour discussing each patient; now it’s time for morning rounds on the floor.
All the patients—some children, some adults—have illnesses affecting multiple systems in their body. Many are dependent on ventilators, feeding tubes and other technology. They are seen by physicians from multiple departments at the hospital. Morin and her colleagues provide the glue.
Some patients are asleep, their families off at work; some are attended by families who sleep in the room with them; others are rarely visited. Some smile and blow raspberries, some have limited or no social interaction. In one room, Morin lingers to talk politics with an adult patient who is still seen at Boston Children’s for his congenital condition. Full story »
Afraa Bakhit, from the Middle East, is among the hospital's most complicated patients. Her disorder is unknown.
This is the first post of a two-part series on children with complex medical needs. Details on some patients have been changed for privacy reasons.
This morning, as every morning, the Complex Care Service (CCS) team huddles in a tiny office deep inside Boston Children’s Hospital. They have 14 patients to discuss, each with a mix of problems that involve multiple clinical departments. Many of them are repeat visitors.
The team begins tackling each case in decreasing order of difficulty. “It seems to be the best way to prioritize the patients with the most immediate needs,” says Mindy Morin, MD, MBA, who’s the attending physician this week. Also on the team are two nurse practitioners, a clinical nurse educator and two resident physicians.
Two-year-old Afraa Bakhit from Dubai tops the list for the sheer number of departments consulting on her case: Genetics, Cardiology, Immunology, Infectious Disease, Rheumatology, Pulmonology, Anesthesia and now a specialist from the Vascular Anomalies Center. Full story »
But for a handful of children, it’s the source of one of the most devastating brain infections known—herpes simplex encephalitis (HSE)—causing fever, confusion, personality changes and seizures. If not caught and treated with high-dose antivirals, it’s highly fatal, and even with treatment most children are left with irreversible brain damage.
Why do some children develop HSE while everyone else just shrugs the virus off? Full story »
It’s been more than a decade since the Human Genome Project cracked our genetic code. DNA sequencing is getting cheaper and cheaper. So why isn’t it being used every day in medicine?
The truth is that while we have the technology to blow apart a patient’s DNA and piece it back together, letter by letter, and compare it with normal “reference” DNA, doctors don’t really know what to do with this information. How much of it is really relevant or useful? Should they be giving it back to patients and their families, and how?
Handled badly, the information could do more harm than good. “We don’t want to scare patients for no reason, or for the wrong reason,” says Isaac Kohane, MD, PhD, who chairs the Children’s Hospital Informatics Program.
Seeking a set of best practices for safe, clinically useful genomic sequencing, Boston Children’s Hospital took a crowd-sourcing approach. Full story »
