Childhood neuronal ceroid‐lipofuscinoses in Argentina

Abstract

We report on 30 cases of neuronal ceroid lipofuscinoses (NCL), mainly diagnosed in 1985–1993 in Argentina, whose population is predominantly of European descent. Twenty‐four cases were late infantile Jansky‐Bielschowsky (LINCL) and 6 were juvenile Spielmeyer‐Vogt (JNCL). Sex ratio was female: male, 20:10. Age range and mean at onset and at diagnosis for the LINCL cases were 1–6 years, mean 3.1, and 2–11 years, mean 5.5, and for the JNCL cases, 5–9 years, mean 7, and 9–18 years, mean 13, respectively. Cases were referred for biopsy after neurological examination, and most included complete electrophysiological [electroencephalography (EEG) with photic stimulation, electroretinography (ERG), and visual‐evoked potential (VEP)], neuroimaging, and neurometabolic investigation. NCL was the first suspected clinical diagnosis, followed by mitochondrial encephalopathy in some cases of recent onset. Except for 1 case, clinical findings were homogeneous in LINCL, characterized by refractive epilepsy, mental regression and progressive deterioration, ataxia, myoclonia, and visual loss. Abnormal VEP, ERG, and EEG, with polyphasic high‐voltage spikes when photic stimulation was performed at low frequency, were observed. Visual impairment and retinitis pigmentosa were early manifestations in 4/6 JNCL, followed by mental abnormalities, motor deterioration, and myoclonic jerks, while 2/4 followed an atypical course. In both variants inheritance was autosomal‐recessive. Five out of 27 families had more than 1 affected member, 3 of whom were included in our series. Diagnosis was initially performed in conjunctival biopsy in 3 cases, skin in 5, muscle in 17, and brain in 5, though most cases had a concomitant biopsy from another tissue including nerve, and there was a single brain autopsy. In the LINCL variant, storage material was mainly curvilinear, also exhibiting dense areas and electron‐lucent vacuoles in 1 case. In addition to fingerprint profiles in 4/6 cases, JNCL biopsies presented curvilinear profiles in a skin biopsy in 1 case, and electronlucent vacuoles in 2 cases in a muscle and brain biopsy coexisting within the same inclusion, with the curvilinear profiles surrounded by a unit membrane, while the other 2/6 had granular osmiophilic inclusions with poorly defined rectilinear areas. The purpose of this report is to describe NCL in a country mainly populated by European descendants, in order to contribute data for further collaborative research.