Preimplantation genetic diagnosis for Zellweger syndrome.

OBJECTIVE: To report on the first live birth of a normal child after performance of preimplantation genetic diagnosis (PGD) for Zellweger syndrome (ZS). DESIGN: Case report. SETTING: Tertiary-care hospital. PATIENT(S): A family with four children diagnosed with ZS, who were all born at term and who expired around 4 months of age. INTERVENTION(S): In vitro fertilization and preimplantation genetic diagnosis. MAIN OUTCOME MEASURE(S): Preimplantation genetic diagnosis of ZS in embryos, and live birth from the transferred normal embryos. RESULT(S): After PGD, two genotypically normal embryos were transferred back to the mother. Pregnancy ensued, and a healthy baby girl was delivered in week 40 of pregnancy. The baby was confirmed as genotypically wild-type, and free of any sign of ZS. CONCLUSION(S): To the best of our knowledge, this is the first successful PGD for ZS caused by mutation in PEX26 gene, with the subsequent delivery of a homozygous normal baby.

Intracytoplasmic sperm injection and conventional in vitro fertilization are complementary techniques in management of unexplained infertility.

PURPOSE: To evaluate the role of ICSI in unexplained infertility. METHODS: In 125 cycles with six or more oocytes retrieved per cycle, sibling oocytes were randomly allocated to IVF or ICSI (group A). In 74 cycles with less than six oocytes retrieved per cycle, cycles were allocated to IVF or ICSI (group B). RESULTS: In group A, ICSI fertilization rate of 61% per allocated oocyte was higher than IVF fertilization rate of 51.6% (P < 0.001). Complete fertilization failure occurred in 19.2 and 0.8% of cycles in IVF and ICSI, respectively (P < 0.001). In group B, fertilization rate in IVF cycles was 53.3% as compared to 60.7% per allocated oocyte in the ICSI cycles (P = 0.29). Complete fertilization failure was higher (P = 0.02) in conventional IVF (34.3%) than ICSI cycles (10.3%). CONCLUSIONS: Allocation of sibling oocytes to IVF and ICSI in the first cycle minimizes risk of fertilization failure. For patients with limited number of oocytes, ICSI technique is recommended.

Nucleolar precursor body distribution in pronuclei is correlated to chromosomal abnormalities in embryos.

In-vitro generated human embryos have low implantation rates and high chromosomal abnormalities. Embryos are mostly selected on the basis of microscopic morphological examination. The relationship between pronuclear morphology and chromosomal abnormalities was investigated in this study. Zygotes were scored according to pronuclear morphology on day 1. Excess embryos that were not transferred or cryopreserved on day 3 were fixed. Chromosomes 13, 18, 21, X and Y were analysed by fluorescence in-situ hybridization (FISH). A total of 125 embryos were analysed; 58 (46%) were abnormal, 32 (26%) were mosaic and 35 (28%) were normal. Results were analysed according to different pronuclear morphology. Zygotes with polarized pattern had a significantly lower incidence of chromosome abnormality than those with a non-polarized pattern. The presence of cytoplasmic halo, the size of each pronucleus and the number of nucleolar precursor body had no significant effect on chromosomal abnormalities. In conclusion, embryos generated from zygotes with polarized pattern have fewer chromosomal abnormalities compared with other patterns. A simple microscopic examination during fertilization confirmation would be useful to select embryos with fewer chromosomal abnormalities, preferably in combination with other observations shown to correlate with chromosomal abnormalities.