[Phenotypic variations in Aicardi-Goutieres syndrome caused by RNASEH2B gene mutations: report of two new cases].

INTRODUCTION: Aicardi-Goutieres syndrome is a rare immune disorder due to mutations in seven different genes that encode proteins called TREX1, ribonuclease H2 complex, SAMHD1, ADAR and IDIH1 (MDA5), which are involved in acid nucleic metabolism. Two cases are described in detail below caused by RNASEH2B gene mutation, one of which displays a mutation no described to date.

CASE REPORTS: Case 1: male consulting because from 5-month-old shows loss of maturity items acquired until then, coming with several fever episodes. Case 2: a 4-month-old boy showing since 2-month-old great irritability and oral-feeding trouble with severe psychomotor impairment. In both cases it was found an increase of pterines in the cerebrospinal fluid, mainly neopterine, with calcifications in the basal ganglia. The diagnosis was proved by sequencing RNASEH2B gene, founding in case 2 a new mutation not described previously.

CONCLUSIONS: The reported cases belong to the description already done by Aicardi-Goutieres, it should be noticed this syndrome in a patient with a subacute encephalopathy of debut in the first year of life, dystonia/spasticity in variable degree and important affectation/regression of psychomotor development, particularly in those with increase of pterines (neopterine) in the cerebrospinal fluid and calcifications in the basal ganglia.