Mom Pushes for Molecular Autopsy After Son's Sudden Death

Damian McNamara

March 09, 2016

LA JOLLA, California — When a 29-year-old man died unexpectedly, his mother refused to accept sudden cardiac death as the cause, and went searching for answers.

Dardanel Robinson, who grew up surrounded by relatives who died in their 40s and 50s, told her story here at the Future of Genomic Medicine IX.

Her grandmother "dropped dead of cardiac death at an early age," she reported. The same happened to her uncles — one at age 42 and the other at age 57 — and to her 52-year-old father.

"I grew up in this atmosphere knowing that people die, and I expected to die young," Robinson said. The single mother of six was a complex civil litigation paralegal in Portland, Oregon, so she knew to prepare a will, insurance papers, and guardianship forms.

In September 2014, Robinson got a call from her son's roommate in Birmingham, Alabama, who had found Daniel blue and unresponsive and called the paramedics, who could not save him.

The cause of death remained a mystery for more than a month as the family waited for the toxicology and autopsy findings.

Was it a mystery even with the family history? asked session moderator Eric Topol, MD, director of the Scripps Translational Research Institute in La Jolla, California, who is editor-in-chief of Medscape.

It was, Robinson replied. "No one died this young. All we knew about was the heart disease."

Dardanel Robinson (Source: Scripps Health)

The medical examiner in Birmingham reported that Daniel likely experienced sudden dysrhythmia that produced a blood clot.

It was then that Robinson began her search. She came across an article in the Los Angeles Times about a study underway at Scripps; researchers were working with the San Diego medical examiner to study cases of unexpected death in young people.

"Our office investigates that subset of deaths that are sudden and unexpected," said Jonathan Lucas, MD, chief deputy medical examiner for San Diego County. "We are in the answer business."

However, "that only gets you so far. Our hope is to be in the prevention business," he added. "The ultimate goal is to help with information that could prevent deaths in the future."

Preliminary study results show a pathogenic mutation — a genetic variant that causes arrhythmia or other cardiac events — in 20% of 30 cases, said Ali Torkamani, PhD, a member of the Scripps team. The goal is to determine the quantitative risk associated with these variants for relatives. "We find living family members carrying these variants and they appear to be totally fine," he reported.

I needed an answer before any more of my children died.

Scripps was not accepting patients outside San Diego for their study, but Robinson was persistent. "I needed an answer before any more of my children died," she said. She asked her children, her brother, and her cousins — 69 relatives in all — to create a multigenerational family tree and urged them to get genetic testing.

During her talk, Robinson implored physicians, researchers, and journalists in the audience to get the word out about tissue preservation to help families like hers.

"The first thing I did was ask [the Birmingham medical examiner] to preserve some samples. As part of my job, when there is a death, I go right to the scene and make sure we preserve evidence," she explained.

"If there is a sudden death in your family, ask them to preserve a sample. They will if you ask, and put it in writing. And if there is an unexplained death in your family and somebody gets sequenced, please look back at your family history," she said.

Although the Scripps researchers did not find anything de novo to explain Daniel's death, they did discover a high occurrence of mutations in the TRPM4 gene in the family, which are known to cause progressive familial heart block.

The TRPM4 gene codes for a protein that opens and closes channels in many cells throughout the body, but is found in particularly high concentrations in heart cells. When there is a mutation in this gene, it can alter the normal beating of the heart and can lead to syncope or sudden cardiac arrest and death, according to the National Library of Medicine Genetics Home Reference website.

Robinson consulted a cardiologist and initially failed a stress test. However, nuclear imaging stress testing showed that she has a healthy heart. "I feel like I dodged a genetic bullet, " she said.

Dr Topol, Dr Torkamani, and Dr Lucas have disclosed no relevant financial relationships.

Future of Genomic Medicine (FOGM) IX. Presented March 3, 2016.


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