Table 1.

Comparison of the major symptoms of patient I and patient II.

Symptoms	Patient I Male, 17 years	Patient II Female, died at the age of 14 months
Neurological symptoms
• General muscular hypotonia	+	+
• Muscular atrophy	+	+
• Areflexia	+	+
• Sluggish sucking reflex	+	+
• Severe psychomotor developmental arrest	+	+
• Absent language development	+	+
• Brain MRI abnormalities	+	+
Visual and auditory symptoms
• Optical nerve atrophy	+
• Deafness	+
Respiratory symptoms
• Respiratory failure	+	+
• Recurrent pneumoniae	+	+
Cardiological symptoms
• Hypertrophic cardiomyopathy of the non-obstructive type	+
Gastroenterological symptoms
• Dysphagia induced malnutrition	+	+
• Reflux disease	+	+
• Gastrostomy tube/nasogastric tube	+	+
Symptoms of the musculoskeletal system
• Inactivity osteoporosis and bone fractures	+
• Scoliosis/hyperlordosis/hypokyphosis	+