Blog | Thursday, March 22, 2012

QD: News Every Day--Marfan syndrome eludes primary care diagnoses

Primary care doctors are only catching one in four cases of Marfan syndrome, and 12% of patients are diagnosed only after the death of a family member.

The National Marfan Foundation surveyed 1,369 Marfan syndrome patients in February to better understand the diagnosis patterns of people with Marfan syndrome.

Early diagnosis, along with new drugs and surgeries, have led to longer life expectancies, but physicians may still rely on decades-old medical school training to spot the symptoms, the chair of the Foundation's professional advisory board said in a press release.

There's a distinct knowledge gap, since the Foundation pointed out that nearly 70% of Marfan's patients report that they were diagnosed before the age of 20. But 18% of respondents said it took an aortic dissection to raise clinical suspicion.

One survey participant explained that, even though the child had a parent with Marfan syndrome and the parents noted that the child had Marfan features, a pediatrician attributed the symptoms to other benign causes. A kindergarten vision exam resulted in a visit to the ophthalmologist, who then sent him to the cardiologist, who confirmed the diagnosis.

The three signs that most often raised the suspicion of Marfan syndrome were long limbs (73%), long, flexible fingers (68%) and height (64%), while indented or protruding chest bone (45%) and scoliosis (33%) were also mentioned.

One-third of respondents (33%) responded that ectopia lentis was the first feature to raise a suspicion of Marfan syndrome. Eye care providers were the first to suspect Marfan syndrome in nearly 20% of cases.

4% of respondents said that a doctor in the emergency department was the first to suspect Marfan syndrome, while in 8%, a relative was the first to suspect the condition.

Simplified diagnostic criteria appeared in the The Journal of Medical Genetics in 2010. This includes a systemic score that assigns Marfan features a numeric value that culminate in a total score. Three significant changes include:
--Aortic root dilatation/dissection and ectopia lentis are weighted more heavily than other characteristics;
--There is a more precise role for molecular testing; and
--Less specific manifestations of Marfan syndrome are either removed or given much less weight in the evaluation process.

Before, evaluation of features were called major or minor.

A mobile website features a summary of the new diagnostic criteria, including seven simple formulae for diagnosing Marfan syndrome, an interactive Systemic Score Calculator, a Z-score calculator used to determine the size of the aorta compared to body surface area, and key points about the role of genetic testing and family history.