Table 2.

Description of all reported mutations affecting the catalytic domain of protein kinase Cγ gene (PRKCG) with the genotype‐phenotype correlation

PRKCG mutations	p.Gly360Ser2	p.Ser361Gly3	p.Ala458Thr (this study)	p.Asp480Tyr31	p.Phe643Leu2, 24	p.Arg659Ser32	p.Val692Gly2	p.Met697Ile33	p.Val177fs31
Type of mutation	Missense	Missense	Missense	Missense	Missense	Missense	Missense	102 base pair deletion	1717 base pair deletion
Conservation	Highly conserved	Highly conserved	Highly conserved	Highly conserved	Highly conserved	Highly conserved	Highly conserved	Highly conserved	Highly conserved
Zygosity	Heterozygous	Heterozygous	Heterozygous	Homozygous	Heterozygous	Heterozygous	Heterozygous	Heterozygous/Homozygous	Heterozygous
Penetrance	100%	100%	100%	100%	100%	100%	100%	100%	100%
Age of onset (years)	53	5‐60	35	NA	Childhood to 60	Not available	20	7‐60	Not available
Symptom at onset	Ataxia	Ataxia	Ataxia	Ataxia	Ataxia	Retinitis pigmentosa	Ataxia	Ataxia	Ataxia
Clinical syndrome	Complex, slowly progressive cerebellar ataxia	Slowly progressive cerebellar ataxia	Complex, slowly progressive cerebellar ataxia	Complex, slowly progressive cerebellar ataxia	Complex, slowly progressive cerebellar ataxia	Not available	Slowly progressive cerebellar ataxia	Complex, slowly progressive cerebellar ataxia	Complex, slowly progressive cerebellar ataxia
Associated features	Rippling in small hand muscles, swallowing difficulties	Depression	Dystonic head tremor with constant titubation of head at rest, laterocollis, severe peripheral neuropathy	Intellectual disability	Cognitive decline (8 cases), myokimia (4 cases), diffuse myoclonus in the limbs (1 case), reduced vibration sense in lower limbs (4 cases), chorea in the hands and head tremor (2 cases)	Not available	Decreased vibration sense	Generalised truncal and limb myoclonus	Intellectual disability
Functional analysis and consequence of mutation	Increased kinase activity, even in the absence of activators.20 Normal dendritic development21	Increased kinase activity within Purkinje cells. Inhibition of dendritic development20, 34	Not available	Not available	Increased kinase activity within Purkinje cells. Inhibition of dendritic development20, 21	Not available	Patterns of kinase activity similar to those of the wild‐type enzyme20	Increased kinase activity compared to wild‐type33	Not available