Part 1: Clinical characteristics
Patients	No	Age range (y)	Same family members	Hearing loss	Tinnitus	Vertigo/ Dizziness	Vision	Somesthesia	CNS	Gaze stabilization	Postural control	Organ failure
Family 1	1	15–19	2, 3, 4	Slight	+		Myopia	Acroparesthesia		Bilateral end-point nystagmus
	2	20–24	1, 3, 4	Slight			Astigmatism	Acroparesthesia
	3	25–29	1, 2, 4	Normal		+	CV, astigmatism, hypermetropia	Acroparesthesia		Bilateral end-point nystagmus
	4	45–49	1, 2, 3	Moderate		+ orthostatic hypotension	Astigmatism, myopia		Cephalalgia (visual)	Vergence deficit
Family 2	5	25–29		Slight				Acroparesthesia		Vergence deficit
	6	30–34	7	Normal			Hypermetropia	Acroparesthesia	MRI periventricular hypersignals			Nephrotic syndrom
	7	60–64	6	Moderate	+	+ orthostatic hypotension				Bilateral end-point nystagmus		Severe HCM
Family 3	8	10–14	9, 10, 11, 12	Slight							Instability
	9	5–9	8, 10, 11, 12	Normal
	10	35–39	8, 9, 11, 12	Unilateral sudden hearing loss	+			Acroparesthesia	MRI periventricular hypersignals	Vergence deficit, saccadic ocular pursuit		HCM
	11	35–39	8, 9, 10, 12	Slight	+	+		Acroparesthesia	Pituitary adenoma		Instability
	12	40–44	8, 9, 10, 11	Slight	+	+ orthostatic hypotension		Acroparesthesia			Instability	Mild HCM
Family 4	13	35–39	14	Slight		+ (VVS, epilepsia)	Astigmatism, myopia		MRI periventricular hypersignals	Bilateral end-point nystagmus, vergence deficit	Instability
	14	40–44	13	Slight		+			Migraine, darkness phobia		Instability
Family 5	15	50–54		Moderate	+	+	CV, astigmatism, hypermetropia	Acroparesthesia		saccadic ocular pursuit		Moderate HCM
Family 6	16	40–44		Moderate			CV, astigmatism, hypermetropia		MRI periventricular hypersignals			ESRD