Deciphering the natural history of SCA7 in children.

BACKGROUND AND PURPOSE: Childhood-onset autosomal dominant cerebellar ataxia type 7 (SCA7) is a severe disease which leads to premature loss of ambulation and death. Early diagnosis of SCA7 is of major importance for genetic counselling and still relies on specific genetic testing, driven by clinical expertise. However, the precise phenotype and natural history of paediatric SCA7 has not yet been fully described. Our aims were to describe the natural history of SCA7 in a large multicentric series of children of all ages, and to find correlates to variables defining this natural history. METHODS: We collected and analysed clinical data from 28 children with proven SCA7. All had clinical manifestations of SCA7 and either a definite number of CAG repeats in ATXN7 or a long expansion > 100 CAG. RESULTS: We identified four clinical presentation patterns related to age at onset. Children of all age groups had cerebellar atrophy and retinal dystrophy. Our data, combined with those in the literature, suggest that definite ranges of CAG repeats determine paediatric SCA7 subtypes. The number of CAG repeats inversely correlated to all variables of the natural history. Age at gait ataxia onset correlated accurately to age at loss of walking ability and to age at death. CONCLUSION: SCA7 in children has four presentation patterns that are roughly correlated to the number of CAG repeats. Our depiction of the natural history of SCA7 in children may help in monitoring the effect of future therapeutic trials.

[The place of neuropathy in the early diagnosis of Cockayne syndrome: Report on two siblings]. / Place de la neuropathie dans le diagnostic précoce du syndrome de Cockayne : à propos de deux cas dans une fratrie.

Two siblings affected with Cockayne syndrome (CS) are described: this diagnosis was suggested by the finding of a demyelinating neuropathy on electromyography in both children and consistent clinical features. CS is a rare genetic disorder with severe prognosis and a highly varied phenotype, making early diagnosis difficult. Taking into account these two cases and the literature, the current diagnosis criteria are insufficiently specific and appear late: the diagnosis may be delayed because multi-organ involvement and sensorial impairment suggests more frequent neurometabolic disorders. Neuroradiologic abnormalities are suggestive but may occur later. The finding of a demyelinating peripheral neuropathy seems to be a more useful marker to suspect this disorder in the presence of other clinical features. Further studies are required to better define the chronology of the symptoms, not only for adequate genetic counseling and eventual prenatal diagnosis, but also to assess the efficacy of future therapies.

[A neonatal case of immunoallergic acute interstitial nephritis]. / Néphropathie interstitielle aiguë immunoallergique néonatale : à propos d'un cas.

Acute interstitial nephritis accounts for about 10 % of the cases of acute renal failure. An adverse drug reaction caused by an immunoallergic mechanism is suggested when fever, skin rash, eosinophilia, and eosinophiluria are associated. The outcome is favorable after withdrawal of drug therapy in most cases. We report a case of acute interstitial nephritis induced by immunoallergic drug mechanisms, in a 3-week-old infant who presented with acute renal failure associated with eosinophilia and hepatitis and who had received cefotaxime and gentamicin. The patient's progression was favorable with normalization of renal and liver function 1 week after suspension of antibiotic drugs.