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Autophagy is required for the homeostasis of cellular material and is proposed to be involved in many aspects of health. Defects in the autophagy pathway have been observed in neurodegenerative disorders; however, no genetically-inherited pathogenic mutations in any of the core autophagy-related (ATG) genes have been reported in human patients to date. We identified a homozygous missense mutation, changing a conserved amino acid, in ATG5 in two siblings with congenital ataxia, mental retardation, and developmental delay. The subjects' cells display a decrease in autophagy flux and defects in conjugation of ATG12 to ATG5. The homologous mutation in yeast demonstrates a 30-50% reduction of induced autophagy. Flies in which Atg5 is substituted with the mutant human ATG5 exhibit severe movement disorder, in contrast to flies expressing the wild-type human protein. Our results demonstrate the critical role of autophagy in preventing neurological diseases and maintaining neuronal health.

We describe a consanguineous Iraqi family in which affected siblings had mild mental retardation and congenital ataxia characterized by quadrupedal gait. Genome-wide linkage analysis identified a 5.8 Mb interval on chromosome 8q with shared homozygosity among the affected persons. Sequencing of genes contained in the interval revealed a homozygous mutation, S100P, in carbonic anhydrase related protein 8 (CA8), which is highly expressed in cerebellar Purkinje cells and influences inositol triphosphate (ITP) binding to its receptor ITPR1 on the endoplasmatic reticulum and thereby modulates calcium signaling. We demonstrate that the mutation S100P is associated with proteasome-mediated degradation, and thus presumably represents a null mutation comparable to the Ca8 mutation underlying the previously described waddles mouse, which exhibits ataxia and appendicular dystonia. CA8 thus represents the third locus that has been associated with quadrupedal gait in humans, in addition to the VLDLR locus and a locus at chromosome 17p. Our findings underline the importance of ITP-mediated signaling in cerebellar function and provide suggestive evidence that congenital ataxia paired with cerebral dysfunction may, together with unknown contextual factors during development, predispose to quadrupedal gait in humans., Competing Interests: The authors have declared that no competing interests exist.

Congenital nonprogressive cerebellar ataxia includes a complex group of disorders with heterogeneous phenotypic and etiopathogenetic characteristics. Despite recent advances in the understanding of the role of the cerebellum in cognition and behavior, the opinion that the clinical presentation of congenital cerebellar diseases is principally linked to motor dysfunction is common. This is largely due to the lack of well-organized epidemiologic studies on the prevalence of nonmotor disturbances in cerebellar disease. The association between congenital cerebellar disease and epilepsy has rarely been described. We report clinical, neurophysiologic, neuroimaging, and neuropsychologic features in a group of 14 patients with congenital nonprogressive cerebellar ataxia associated with cerebellar hypoplasia, 5 of whom have familial disease, aiming to further a better knowledge of the prevalence of cognitive and/or emotional impairment and epilepsy. The results confirm that cerebellar hypoplasia predisposes individuals to psychomotor delay (71.4%) and cognitive impairment (85.7%). Moreover, the tendency toward abnormal electroencephalographic (EEG) findings (78.5%), associated in a minor percentage of cases with epilepsy (28.5%), is also evident in our study.

Nonprogressive congenital ataxia is a complex group of disorders caused by a variety of etiologic factors, both environmental and genetic. Hereditary forms represent a substantial part of congenital ataxias, which are difficult to classify because of their phenotypic and genetic polymorphism. Despite the advances in molecular genetics, for most nonprogressive congenital ataxia the etiology is still unknown. This report describes three sons of nonconsanguineous healthy parents, who manifested a syndrome characterized by nonprogressive ataxia, mental retardation, pyramidal signs, ocular and ocular motor anomalies, associated with severe hypoplasia of the cerebellar vermis and hemispheres on neuroimaging. All the patients have presented psychomotor developmental delay. As differential diagnosis, a comparison is made between the clinical features of these patients and the previously reported cases of nonprogressive congenital ataxia. This report represents a further example of the phenotypic and genetic heterogeneity of the syndromes with congenital ataxia.

Here, we describe a 20-yr-old woman with COACH syndome (hypoplasia of Cerebellar vermis, Oligophrenia, congenital Ataxia, Coloboma, and Hepatic fibrosis) developing multiple liver lesions. Epigastric and right upper abdominal pain and lack of appetite led to clinical evaluation. Liver function tests showed an increase in transaminases and cholestatic parameters; alpha-fetoprotein was in the normal range. Ultrasound and magnetic resonance imaging examinations revealed multiple liver lesions. Histological examinations of ultrasonographically guided biopsies were consistent with regenerative hepatic nodules without features of malignant or dysplastic cells. The sizes of these tumors did not change over a period of 12 months. Our report presents the 10th case of COACH syndrome with a hitherto undescribed association with hepatic tumors.

Congenital hepatic fibrosis (CHF) is probably the most common cause of non-icteric hepatosplenomegaly and is encountered mainly in children and young adults. We describe here two brothers from healthy, non-consanguineous parents. The patients showed early hepatosplenomegaly, portal hypertension, and no apparent kidney involvement. Clinical and laboratory findings were similar in both patients. Liver biopsies showed the presence of broad septa of fibrous tissue containing abundant bile ducts, portal tracts enlarged by fibrosis, and preserved lobular architecture. The histological findings were suggestive of CHF. Ophthalmological assessment demonstrated visual impairment with mild exotropia, nystagmus, and oculomotor apraxia. Neurological examination showed moderate mental retardation and cerebellar ataxia. Brain MRI confirmed cerebellar malformation with inferior vermis hypoplasia. This pattern of defects is consistent with COACH syndrome (Cerebellar vermis hypoplasia, Oligophrenia, congenital Ataxia, Coloboma, Hepatic fibrocirrhosis) which has previously been reported in five other cases. Our report may contribute to a better delineation of the COACH syndrome phenotype in the spectrum of oculo-encephalohepato-renal disorders.

Linkage analysis was performed in a previously described family segregating for an X-linked progressive neurological disorder [Bertini et al., 1992]. In three generations, the disease was inherited from the mothers in seven affected males (Fig. 1). Five had severe congenital hypotonia and died during the first year of life. Two other boys (maternal cousins) were found to have severe congenital ataxia, late-onset progressive myoclonic encephalopathy, and selective macular degeneration; brain CT-scan showed moderate cerebellar vermis hypoplasia. Linkage analysis was carried out in 12 informative relatives using 35 microsatellite markers (Généthon) evenly distributed on the X chromosome. A multipoint analysis showed a significant linkage (Z > 2) between the disease and three markers in the Xp22.33 region: DYS403 (Z = 2.37, theta = 0) which maps in the pseudoautosomal region, DXS7099 (Z = 2.45, theta = 0), and DXS7100 (Z = 2.48, theta = 0). Further linkage analysis with more telomeric markers will refine the location of this severe X-linked encephalopathy.

Van Maldergem et al. (1992) described a new syndrome in an 11-year-old girl, characterized by: mental retardation, hypotonia, dysmorphic facies with telecanthus, epicanthus, broad flattened nose, large inverted W-shaped mouth, malformed ears, finger camptodactyly, and joint hyperlaxity. In this report we present a 5-year-old girl with very similar clinical findings. We confirm the existence of this condition as an independent clinical entity, and we propose that, based on the major clinical manifestations, it should be defined as "cerebro-facio-articular" syndrome.