Fetal MRI findings in a retrospective cohort of 26 cases of prenatally diagnosed CHARGE syndrome individuals.

"CHARGE syndrome" (CS) is a multifaceted syndrome associated with a poor prognosis. The prenatal diagnosis remains challenging especially as the fetal anomalies that may evoke suspicion of CS are not comprehensively described. OBJECTIVE: This study aims to identify the anomalies in MRI with suspected CHARGE syndrome and to propose a possible standardization in the image-based prenatal diagnosis of CS. METHODS: This was a retrospective study of 26 fetuses who underwent MRI and had a confirmed diagnosis of CS, as proven by histopathological and/or neonatal examinations and/or the presence of the CHD7 gene mutation. RESULTS: The three most frequent MRI anomalies confirmed at histopathological and/or neonatal examinations were arhinencephaly in 100% (26 of 26), dysplasia of the semicircular canals agenesis (SCA) in 100% (24 of 24), and posterior fossa anomalies in 100% (22 of 22). Our study also revealed short petrous bones with a particular triangular shape in 24 of 24 cases of SCA. Other relevant findings included external ear anomalies in 36% (9 of 25), cleft lip and palate (9 of 9), ventriculomegaly (VMG) (6 of 6), short corpus callosum (3 of 3), and ocular asymmetry in 36.6% (4 of 11). CONCLUSION: Our study emphasizes the interest of fetal MRI in the diagnosis of CS with an adapted knowledge of semiology.

[Preimplantation genetic diagnosis: update of the Parisian group]. / Le diagnostic génétique préimplantatoire: premier bilan du groupe parisien.

To report the birth of the first fourteen infants conceived after preimplantation genetic diagnosis (PGD) in our unit. Fifty-nine couples were enrolled between January 2000 and July 2001. They had a total of 71 oocyte pick-up cycles. The collected oocytes were inseminated by intracytoplasmic sperm injection. The resulting embryos were biopsied on the third day of development and the genetic analysis was performed on the same day. Most of the embryo transfers were carried out on the fourth day. The 71 oocyte pick-up cycles yielded 872 oocytes of which 731 were suitable for intracytoplasmic sperm injection. Among the 505 embryos obtained, 421 embryos were biopsied and genetic diagnosis was performed for 312 (74%) of these 127 embryos were transferred during the course of 58 transfer procedures. There were 18 biochemical and 12 ongoing (7 singles, 4 twins and 1 triple) pregnancies. Sixteen infants have been born and 2 are expected. PGD has gained a place among the choices offered to couples at risk of transmission of a serious and incurable genetic disease.

Podocin localizes in the kidney to the slit diaphragm area.

We recently cloned a novel gene, NPHS2, involved in autosomal recessive steroid-resistant nephrotic syndrome. This gene encodes a novel podocyte protein, podocin. Given its similarity with the stomatin family proteins, podocin is predicted to be an integral membrane protein with a single membrane domain forming a hairpin-like structure placing both N- and C-termini in the cytosol. Here, we show by in situ hybridization, that during development, the NPHS2 transcript is first expressed in mesonephric podocytes from the S-shaped body and, later, in the metanephric kidney, in the future podocytes at the late S-shaped body stage. In the mature kidney, NPHS2 is exclusively expressed in the podocytes of mature glomeruli. We generated rabbit polyclonal antibodies against fusion proteins derived from the N- and the C-terminal regions of podocin which detected a single band of 49-kd in transfected HEK293 cell lysates by immunoprecipitation and Western blotting. By immunohistology, podocin was detected in podocytes from the early capillary loop stage in the developing nephrons, and at the basal pole, along the GBM, in mature glomeruli. By electron microscopy, we demonstrate that podocin is facing the slit diaphragm with its two ends in the cytoplasm of the foot processes, in agreement with its predicted structure. Our results suggest that podocin could serve to anchor directly or indirectly components of the slit diaphragm to the cytoskeleton.

Birth of healthy female twins after preimplantation genetic diagnosis of cystic fibrosis combined with gender determination.

Two healthy sisters with a familial history of mental retardation were referred to our centre for preimplantation genetic diagnosis (PGD). Their two brothers showed severe mental retardation. The molecular basis for their disorder could not be identified, but one of the sisters and the mother presented a highly skewed pattern of X-inactivation reinforcing the likelihood of an X-linked mode of inheritance. Both sisters requested PGD to avoid the abortion of potentially affected male fetuses. PGD for sex by fluorescent in-situ hybridization was carried out for the first sister and resulted in the birth of a female child. The second sister and her partner, whose niece had cystic fibrosis (CF), were tested for CF mutations, and were both found to be deltaF508 heterozygous. We developed an efficient single cell PCR protocol for the simultaneous amplification of the CF (deltadeltaF508) locus as well as the X-linked amelogenin gene and its highly homologous pseudogene on the Y chromosome. Two PGD cycles were carried out to screen against male and deltaF508 homozygous deleted embryos. In each case several embryos could be selected for transfer and the second cycle resulted in a twin pregnancy followed by the birth of two healthy female infants.