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Reports of terminal and interstitial deletions of the long arm of chromosome 2 are rare in the literature. Here, we present a case report concerning a Chinese boy with a 47,XYY karyotype and a de novo deletion comprising approximately 5 Mb between 2q35 and q36.1, along with syndactyly, type III Waardenburg syndrome, and congenital heart disease. High-resolution chromosome analysis to detect copy number variations was carried out using an Affymetrix microarray platform, and the genes affected by the patient's deletion, including IHH, were determined. However, no copy number changes were observed in his healthy parents. The present case exhibited novel syndactyly features, broadening the spectrum of clinical findings observed in individuals with 2q interstitial deletions. Our data, together with previous observations, suggest that IHH haploinsufficiency is the principal pathogenic factor in the syndactyly phenotype in this study, and that different types of variations at the IHH locus may cause divergent disease phenotypes. This is the first report of the involvement of IHH haploinsufficiency in syndactyly phenotype.

The multiplex amplification system of three tetrameric short tandem repeats loci (D16S539, D7S820, and D13S317) have been analysed extensively in various populations for forensic application. Population genetic studies were carried out for these three loci in a population sample of 129 unrelated Tibetan individuals by using a multiplex polymerase chain reaction (PCR) followed by 4% polyacrylamide gel electrophoresis (PAGE) and silver staining. All loci were in accordance with the Hardy-Weinberg expectations. The observed heterozygosities of three loci-D16S539, D7S820, and D13S317 were 73.3%, 81.4% and 80.6%, respectively. The polymorphism information contents (PIC) were 0.84, 0.80 and 0.83, respectively. Comparing with Han population, there was no statistically significant difference except for D16S539 locus.

We constructed a plasmid that contains a small piece of DNA with two vaccinia promoters running in opposite directions--a promoter from a late gene encoding an 11 K polypeptide (P11) and a promoter from an early gene encoding 25K (P25). These promoters were isolated from the Tian Tan strain of vaccinia virus and were flanked by the thymidine kinase (TK) sequence of the same virus. Genes encoding the hepatitis B virus surface antigen (HBsAg) and the Escherichia coli beta-galactosidase (LacZ) were inserted downstream of the 11 K and 25 K promoters respectively so that coexpression plasmids were constructed. Recombinant vaccinia viruses were selected directly by picking blue plaques formed under overlaying agarose medium containing X-gal. HBsAg was expressed to high level by these recombinant viruses. These recombinant viruses showed reduced virulence on rabbit skin and induced anti-HBs after intradermal inoculation of rabbits.

The origin and characteristics of the first naturally occurring temperature-sensitive (ts) strain of influenza A virus identified in 1973, Xia-ts, are described. Natural ts strains were found to occur in the early egg passage material of all influenza A subtypes examined, but the proportion of ts virus varied from 8.3% for old H1N1 virus (1949 to 1957) to 82.4% for recent H3N2 virus (1979 to 1980). A number of strains were found to be composed of a mixture of ts and wild-type (ts+) particles. Six natural ts strains with different shutoff temperatures and one ts+ strain of the H1N1 subtype were tested in antibody-free volunteers. Strains with a shutoff temperature of 38 degrees C or lower caused very mild symptoms, whereas those with a shutoff temperature of 39 degrees C and the ts+ strain were much more reactogenic. By complementation tests against a set of prototype WSN ts mutants with a defined genetic lesion, the ts lesion of two H3N2 viruses (HK/8/68 and Xia-ts) was located on the NP gene and that of two H1N1 viruses (Tianjin/78/77 and Beijing/1/79) was located on the M protein gene. The present study demonstrates the widespread occurrence in nature of influenza viruses of different degrees of temperature sensitivity and presumably of different degrees of virulence.

A late gene coding for a major structural polypeptide of 11,000 daltons from the Tian Tan strain of vaccinia virus was cloned. A comparison of the sequences from Tian Tan and WR strains of vaccinia virus revealed that there were differences in four nucleotides and one amino acid and that there was little homology between the 5'-flanking sequences of the late and the early genes. However, substantial homology was detected between the 5'-flanking sequences of the late genes.

Using cloned viruses of proven purity, and by the methods of hemagglutination inhibition, single radial hemolysis, strain-specific complement fixation and neutralization tests we have demonstrated the serological cross reaction between late H1N1 variant (Dutch/56) and H2N2 of influenza A virus with fowl and hamster antisera. Such a cross reaction is not detected with earlier H1N1 variants. Serological crossing covers variants of H2N2 virus isolated from 1957-1966 but in decreasing titers, and disappears with the last variant of H2N2 isolated late in 1967. Analysis with mono-specific antisera or antigens prepared with recombinants reveal that the hemagglutinins of late H1N1 and H2N2 are related, while their neuraminidases are distinct. We have discussed the bearing of such antigenic relationships to previous epidemiological observations on the partial protection of patients convalescent from late H1N1 disease against H2N2 and to the recombination theory for the origin of H2N2 virus.