Clinical spectrum associated with some structural cerebellar abnormalities

Objectives: To review the clinical, neuroimaging,cytogenetic, and biochemical studies obtained in 20patients with different cerebellar structural abnormalitiespresenting at variable ages of onset with variable signs andsymptoms.Methods: These patients visited the Clinical GeneticsDepartment, National Research Center, Cairo, Egypt duringthe period from September 2002 to September 2003. Allpatients were subjected to complete personal and familyhistory taking 3 generation family pedigree constructionand full clinical examination, including complete eyeevaluation. Metabolic screening, chromosomal examinationand brain CT or MRI, or both, were also carried out.Results: Patients with cerebellar structural abnormalitieswere broadly divided into those with cerebellar hypoplasia(15 patients; 75%), cerebellar atrophy (3 patients; 15%)and cerebellar white matter abnormalities (2 patients;10%). Further, cerebellar hypoplasia was subdivided intoABSTRACTcerebello-vermal hypoplasia (4 patients; 20%), vermalcerebellarhypoplasia (3 patients; 15%) and associatedwith involvement of other features such as brain stem(4 patients; 20%), posterior fossa (1 patient; 5%); andintracranial calcification (3 patients; 15%).Conclusion: This study showed that the type of cerebellarstructural abnormality is not the main determining factor ofthe clinical outcome, but rather the underlying etiology. Ahigh incidence of mostly autosomal-recessive inheritancewas diagnosed in 65% of the patients with cerebellarstructural abnormalities. Nevertheless, the high rate ofconsanguinity (18 cases; 90%) with mean inbreedingcoefficient of 0.05312 and the similarly affected sibshighlights the role of the autosomal recessive gene in ourcountry