Meeting NewsPerspective

Ocular geneticists find high rate of misdiagnosis of Stargardt disease

Manuel B. Ibanez

PHILADELPHIA — Ocular geneticists found a near 37% rate of misdiagnosis of Stargardt disease, which highlights the need for more specialists in a rare field, according to a study presented here.

“Stargardt diagnosis can be challenging due to the heterogeneity,” Manuel B. Ibanez IV, MD, DPBO, said at the Wills Eye Conference. Familiarity with genotypes/phenotypes associated with such a heterogenous disease is key to making the correct diagnosis, he said.

The retrospective analysis included 41 patients with a diagnosis of Stargardt disease who were referred to Wills Eye Hospital between 2015 and 2018. Using a standard definition for the disease, Ibanez and colleagues performed phenotype assessment to group patients as being “likely” or “not likely” to have Stargardt disease.

DNA testing confirmed nine patients had neither Stargardt disease nor ABCA4 mutation, which can cause Stargardt-like disease, and three patients did not have Stargardt disease but did have ABCA4 mutation. Three other patients were found “not likely” to have Stargardt disease by phenotype assessment, but no DNA testing was done.

The misdiagnosis of the 15 patients (36.6%) emphasizes the need for accuracy in diagnosis that ocular geneticists can provide, particularly when formulating treatment trials, Ibanez said. – by Scott Buzby

 

Reference:

Ibanez MB IV. Stargardt misdiagnosis: how ocular genetics helps. Presented at: Wills Eye Conference; Mar. 7-9, 2019; Philadelphia.

Disclosure: Ibanez reports no relevant financial disclosures.

Manuel B. Ibanez

PHILADELPHIA — Ocular geneticists found a near 37% rate of misdiagnosis of Stargardt disease, which highlights the need for more specialists in a rare field, according to a study presented here.

“Stargardt diagnosis can be challenging due to the heterogeneity,” Manuel B. Ibanez IV, MD, DPBO, said at the Wills Eye Conference. Familiarity with genotypes/phenotypes associated with such a heterogenous disease is key to making the correct diagnosis, he said.

The retrospective analysis included 41 patients with a diagnosis of Stargardt disease who were referred to Wills Eye Hospital between 2015 and 2018. Using a standard definition for the disease, Ibanez and colleagues performed phenotype assessment to group patients as being “likely” or “not likely” to have Stargardt disease.

DNA testing confirmed nine patients had neither Stargardt disease nor ABCA4 mutation, which can cause Stargardt-like disease, and three patients did not have Stargardt disease but did have ABCA4 mutation. Three other patients were found “not likely” to have Stargardt disease by phenotype assessment, but no DNA testing was done.

The misdiagnosis of the 15 patients (36.6%) emphasizes the need for accuracy in diagnosis that ocular geneticists can provide, particularly when formulating treatment trials, Ibanez said. – by Scott Buzby

 

Reference:

Ibanez MB IV. Stargardt misdiagnosis: how ocular genetics helps. Presented at: Wills Eye Conference; Mar. 7-9, 2019; Philadelphia.

Disclosure: Ibanez reports no relevant financial disclosures.

    Perspective

    Ocular genetics is a rare specialty. There are only 70 to 80 of us in the world, and we are basically rare disease doctors. We spend all day every day seeing rare disorders over and over, which gives us a special familiarity, not only with clinical diagnosis but also with genetic diagnosis, which is very complex and difficult. For every hour we spend with the patient, we spend about 10 hours figuring out what they have and the interpretation of their genetic tests. Using an ocular geneticist will increase diagnostic rate accuracy. As well, in the context of treatment trials and gene therapy, we can ensure treatment is going to the right patient with the right disorder. It is becoming critical to give better counseling to patients and better treatment options; there are so many spin-offs to having the right diagnosis. This study will mean two things in particular for clinicians. First, this study gives a sense of what this new specialty is and how we can help, so that clinicians can best make use of us to give them those correct diagnoses. Second, as treatment trials roll out, it is going to mean that doctors can now connect their patients more accurately with what they need. You shouldn’t put a cast on an arm for a broken leg.

    • Alex V. Levin, MD, MHSc, FRCSC
    • Wills Eye Hospital, Philadelphia

    Disclosures: Levin reports no relevant financial disclosures.

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