ABSTRACT
Joubert syndrome (JS) is an autosomal recessive developmental brain condition characterized by hypoplasia/dysplasia of the cerebellar vermis and by ataxia, hypotonia, oculomotor apraxia, and neonatal breathing dysregulation. A form of JS that includes retinal dysplasia and cystic dysplastic kidneys has been differentiated from other forms of JS, called either "JS type B" or "cerebello-oculo-renal syndrome" (CORS), but the genetic basis of this condition is unknown. Here, we describe three consanguineous families that display CORS. Linkage analysis defines a novel locus on chromosome 11p12-q13.3, with a maximum two-point LOD score of Z=5.2 at the marker D11S1915. Therefore, the cerebello-oculo-renal form of JS is a distinct genetic entity from the Joubert syndrome 1 (JBTS1) locus described elsewhere, in which there is minimal involvement of retina or kidney. We suggest the term "CORS2" for this new locus.
Subject(s)
Brain/abnormalities , Cerebellum/abnormalities , Chromosomes, Human, Pair 11 , Kidney Diseases, Cystic/genetics , Retina/abnormalities , Chromosome Mapping , Female , Genetic Linkage , Humans , Magnetic Resonance Imaging , Male , SyndromeABSTRACT
This unit presents protocols for sperm isolation using two different methods, amplification of simple sequence-length polymorphisms (SSLP) and/or single nucleotide polymorphisms (SNP) from single cells or whole genome-amplified single cells using primer extension preamplification (PEP), and discusses the statistical analysis of sperm-typing recombination data. Newer methods for studying recombination over very short distances (a few kilobases) using total sperm DNA and allele-specific PCR are also discussed.
