Andersen syndrome autosomal dominant in three generations

Area of Science:

• Genetics and rare diseases
• Cardiology
• Neurology

Background:

• Andersen syndrome is a rare genetic disorder characterized by periodic paralysis, ventricular arrhythmias, and distinct facial features.
• Early diagnosis is crucial for managing severe systemic manifestations, including syncope and sudden death.
• While not directly linked to other periodic paralyses or Long QT syndrome, a prolonged QT interval is often observed.

Observation:

• This report describes a three-generation family with 10 affected members, representing the largest family cohort documented.
• Additional minor anomalies like a broad forehead and malar hypoplasia were noted in affected individuals.
• Clinical presentation exhibited variable expression of the classical triad and systemic manifestations.

Findings:

• A significant proportion of affected individuals (5 out of 8 studied) did not present with a prolonged QTc interval.
• This finding challenges the notion that a long QTc is a constant feature of Andersen syndrome.
• The study underscores the variability in disease expression within families.

Implications:

• The findings emphasize the need for careful clinical evaluation beyond a single diagnostic marker.
• Recognizing the characteristic facial features remains key for early diagnosis and management.
• Further research is needed to understand the full spectrum and genetic underpinnings of Andersen syndrome.