We report a direct DNA sequencing analysis of the MECP2 gene undertaken on a further 64 Italian patients with Rett syndrome by using a LICOR 4200 Automated Sequencer. All of the girls entering the study had a consistent clinical diagnosis for this disorder. All coding regions and the flanking intronic splice site sequences were amplified as three non-overlapping fragments by using both forward and reverse primers. The results were then compared to the MECP2 reference sequences published in GenBank. Mutations of the MECP2 gene were identified in 64 of 75 (85.33%) unrelated sporadic Rett syndrome girls. Genotype/phenotype correlation studies, in particular in groups of patients with the same mutation, did not offer definitive and interesting data.

We used an infrared (IR) automated fluorescence monolaser sequencer for the analysis of 13 autosomal short tandem repeat (STR) systems (TPOX, D3S1358, FGA, CSF1PO, D5S818, D7S820, D8S1179, TH01, vWA, D13S317, D16S359, D18S51, D21S11) and the X-Y homologous gene amelogenin system. These two systems represent the core of the combined DNA index systems (CODIS). Four independent multiplex reactions, based on the polymerase chain reaction (PCR) technique and on the direct labeling of the forward primer of every primer pair, with a new molecule (IRDye800), were set up, permitting the exact characterization of the alleles by comparison with ladders of specific sequenced alleles. This is the first report of the whole analysis of the STRs of the CODIS core using an IR automated DNA sequencer. The protocol was used to solve paternity/maternity tests and for population studies. The electrophoretic system also proved useful for the correct typing of those loci differing in size by only 2 bp. A sensibility study demonstrated that the test can detect an average of 10 pg of undegraded human DNA. We also performed a preliminary study analyzing some forensic samples and mixed stains, which suggested the usefulness of using this analytical system for human identification as well as for forensic purposes.