1. MOLECULAR BASIS OF MUTATION KISHOR SAWAIKAR R A C WASHIM (MS) INDIA

10. Molecular Basis of Gene Mutation Mutations are changes in the DNA sequence of genes. Point mutations typically refer to alterations of single base pairs of DNA or of a small number of adjacent base pairs. Mutations in DNA caus e substitutions in protein

21. <> X-linked inheritance Asymptomatic, hemizygous fathers pass &quot; fragile X &quot; chromosome to daughters Heterozygous daughters transmit to 1/2 of sons, who show syndrome 1/2 of daughers are carriers Syndrome becomes more pronounced in successive generations expansioin of repeat occurs in female germline # CGG repeats Geno / Phenotype 6 ~ 54 standard ~ 55 ~ 200 carrier > 200 Fragile-X Syndrome