The polyG diseases: a new disease entity

Table 1 Phenotypic features of polyG diseases

	FXTAS	NIID	OPML	OPDM
	FXTAS	NIID	OPML	OPDM1	OPDM2	OPDM3	OPDM4
Mode of inheritance	XL	AD	AD	AD	AD	AD	AD
Affected genes	FMR1	NOTCH2NLC	NUTM2B-AS1	LRP12	GIPC1	NOTCH2NLC	RILPL1
Gene location	Xq27.3	1q21.2	10q22.3	8q22.3	19p13.12	1q21.2	12q24.31
CGG expansion location	5’UTR	5’UTR	Non-coding Transcript	5’UTR	5’UTR	5’UTR	5’UTR
Physiological repeat numbers	5–50	7–40?	3–16	13–45	12–32	7–40?	9–16
Pathological repeat numbers	55–200	60–300	50–60	85–289	73–164	60–300	139–197
Age of onset (years)	> 50	most > 50	15–40	30–50	20–60	20–50	15–40
Clinical features
Movement disorders	+ + +	+	+	+	+	+	+
Cognitive deficit	+	+ + +	±	−	+	+	−
Autonomic dysfunction	+ + +	+ + +	+	−	−	+	−
Muscle-weakness	+	+	+	+ +	+ +	+ +	+ +
Others	neuropsychosis	encephalitic episodes	myocardiopathy	myocardiopathy	−	−
Neuroimage features
Brian atrophy	+	+	+	−	−	+	−
Leukoencephalopathy	+	+	+	−	+	+	−
Ribbon sign	±	+	±	−	−	±	−
Pathology
Eosinophilic inclusions	+	+ + +	−	+	+	+	+
Tubulofilamentous inclusion	+	+	−	+	+	+	+
Ubiqutin- or p62- positive	+	+	N/A	+	+	+	+
PolyG-positive	+	+	(polyG)?	(polyG)?	(polyG)?	+	(polyG)?
Rimmed vacuoles in muscle	−	±	−	+	+	+	+

AD Autosomal dominant; XL X-linked dominant; AR Autosomal recessive; N/A not available; UTR untranslated region
+ + + , most positive; + + , some positive; + , a few positive; ± , occasionally positive; −, negative
FXTAS fragile X-associated tremor ataxia syndrome; NIID neuronal intranuclear inclusion disease; OPML oculopharyngeal myopathy with leukoencephalopathy; OPDM1 oculopharyngodistal myopathy type 1–4; polyG polyGlycine peptide toxicity

ISSN: 2051-5960