Syndactyly type 1 (SD1) is the most common type of syndactyly, inherited in an autosomal dominant fashion and characterized by complete or partial webbings between the third and fourth fingers and/or between the second and third toes. We recently encountered an Iranian family in which 33 members in six generations were affected with SD1. As a locus of SD1 in a German family has recently been assigned to chromosome 2q34-q36, we performed a linkage analysis of the Iranian SD1 in order to know whether the disorder is genetically homogeneous. With the analysis on 15 affected and 16 unaffected persons in the Iranian family, using dinucleotide repeat polymorphisms as markers, we mapped the SD1 locus to 2q34-q36 with a maximum LOD score of 6.92 at a recombination fraction straight theta = 0.00 (penetrance = 1.00) for the D2S2179 locus. The result not only confirmed the gene assignment, but also suggests genetic homogeneity of the disease.

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In relation to the growing recent interest in the establishment of sperm-mediated gene transfer (SMGT) technology as a convenient and effective method for the simple production of transgenic animals, in this study the possibility of using SMGT to produce transgenic caprine embryos was investigated for the first time. Buck sperm were directly incubated with different concentrations (0-500 ng) of pcDNA/his/Lac-Z plasmid and used for IVF or ICSI. Sperm used for ICSI were categorized into motile or live-immotile group before being injected into oocytes. In a separate experiment, dead sperm prepared by repeated freezing/thawing were used for DNA-incubation before ICSI. Sham injection was carried out by intracytoplasmic injection of approximately the same volume of media containing different doses of DNA using an ICSI needle. Transgene expression and transmission were detected by X-Gal staining and PCR analysis of developed embryos, respectively. A reasonable blastocyst rate was observed in all the groups. Only embryos in the sham group were negative for transgene transmission. Transgene expression was completely dependent on the delivery technique and status of sperm, and was only observed in the live-immotile and dead ICSI groups. The results of this study showed that the technique (IVF vs. ICSI vs. sham injection), sperm status (motile vs. live-immotile vs. dead) and to some extent DNA concentration affect embryo development, transgene transmission and expression.

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Bardet-Biedl syndrome (BBS) is a group of autosomal recessive MCA/MR syndromes characterized by pigmentary retinopathy, postaxial polydactyly, hypogenitalism, obesity, and mental retardation. Five BBS loci have been identified; among them, BBS type 1 (BBS1) and type 3 (BBS3) are most common and most rare, respectively. We encountered an Iranian family that had seven affected members. All patients had a history of mild to severe obesity, but it was reversible in some patients by caloric restriction and exercise. All patients had pigmentary retinopathy, beginning as night blindness in early childhood and progressing toward severe impairment of vision by the end of the second decade. Polydactyly varied in limb distribution, ranging from four-limb involvement to random involvement or even to nonaffectedness. Six of the seven patients were not mentally retarded. Although kidney anomaly or an adrenal mass was present in two patients, the fact that one patient had seven children rules out reproductive dysfunction. Linkage analysis with microsatellite markers showed that the disease in the family was assigned to a region around marker loci at 3p13-p12 (maximum LOD score = 4.15 and recombination fraction = 0, at D3S1603 microsatellite marker), to which the BBS3 locus has been mapped.