Different proximal and distal rearrangements of chromosome 7q associated with holoprosencephaly.

Four new cases of holoprosencephaly are described in fetuses exhibiting abnormal karyotypes with different distal and proximal rearrangements of the long arm of chromosome 7. Three of them showed terminal deletions of chromosome 7q, confirming the importance of the 7q36 region in holoprosencephaly. The karyotype of the fourth fetus showed an apparently balanced de novo translocation, t(7;13) (q21.2;q33), without any visible loss of the distal part of chromosome 7q. The involvement of new genes, different from the human Sonic Hedgehog gene (hShh) responsible for holoprosencephaly, or a positional effect are discussed.

[Acardiac fetus]. / Foetus acardiaque.

Acardiac fetus is a rare lethal fetopathy usually encountered in monozygous pregnancies. Ultrasound prenatal diagnosis has enabled an increasing number of observations and raised the need for an adequate therapeutic approach since the spontaneous prognosis for the healthy twin is unfavorable in half of the cases. An acardiac fetus was identified at 12 weeks gestation in a 36-year-old woman. Growth of the healthy fetus was carefully monitored and progressed normally to delivery by cesarean section of a 2.900 kg boy at 36 weeks. At delivery, the acardiac fetus was found to be totally free of any attachment, floating in the remaining fluids. Pathology examination showed a 16 g macerated fetus with a cephalic extremity, a ventral pedicle and a syrenomelic caudal extremity. The caryotype was not significative. Acardiac fetus occurs in less than 1% of multiple pregnancies and can develop in single pregnancies. Twin reversed arterial perfusion has been recognized as necessary for development of the perfused fetus. Genetic and immunologic theories have been proposed to explain the pathogenesis which remains unknown. Clinical management depends on the spontaneous development of the acardiac fetus and the deleterious consequences for the healthy twin resulting from heart failure, anasarca or prematurity. Medical management with digoxin, or selective extraction by hysterotomy may improve prognosis but results have been variable. Echoguided umbilical cord ligation has also been proposed to improve maternal mortality. Therapeutic abstention is no longer indicated at prenatal diagnosis of an acardiac fetus and a healthy twin despite the risk of invasive treatment.

Congenital hypothalamic hamartoma syndrome: nosological discussion and minimum diagnostic criteria of a possibly familial form.

We report on congenital hypothalamic hamartomas, discovered at autopsy in 3 unrelated fetuses. In the first 2 patients, the tumor was associated with skeletal dysplasia only. In the third patient, it was part of a non-random congenital malformation association, suggestive of Meckel syndrome. In one family, a previous boy died soon after birth with similar craniofacial and skeletal abnormalities. As far as we know, the association between isolated skeletal dysplasia and congenital hypothalamic hamartomas has not yet been documented in the literature. Nevertheless, a spectrum of skeletal abnormalities has been described in association with congenital hypothalamic "hamartoblastoma" and a constellation of variable visceral malformations under the eponym of "Pallister-Hall syndrome" (PHS). A detailed analysis of the PHS reported cases shows that only skeletal dysplasia and oro-facial abnormalities are present constantly. They show similarities with those found in our first 2 cases. These findings prompt us to consider skeletal dysplasia and oro-facial abnormalities as common denominator and minimum criteria required to define a nosologically distinct, possibly familial entity, which we suggest calling "congenital hypothalamic hamartoma syndrome" (CHHS).

Fetal hydrocephalus. Clinical significance of associated anomalies and genetic counseling: a pathological approach.

We report on a consecutive series of 94 cases of fetal hydrocephalus. Pathological and neuropathological findings have been thoroughly analysed in order to define more precisely the clinical significance of associated anomalies and their implications in genetic counseling. In 90.5% of cases, hydrocephalus was associated with other central nervous system (84%) or extra neural (56%) anomalies. True aqueductal stenosis occurred only twice in our series. In only 9 fetuses, hydrocephalus was an isolated finding, secondary to haemorrhage or infection. Since fetal hydrocephalus is an etiologically heterogeneous disorder, its recurrence varies greatly. Without a final diagnosis, based on well documented pathological data and cytogenetic studies, accurate genetic counseling and prenatal diagnosis in subsequent pregnancies would be impossible.

[The incidence of congenital malformations. A five-year study carried out in a Paris maternity unit (author's transl)]. / Fréquence des malformations à la naissance. Etude d'une maternité parisienne pendant cinq ans.

The congenital malformations arising out of 13,335 deliveries that occurred over the course of five years in the University Clinic of Gynecology and Obstetrics in the hospital of Saint-Antoine were recorded. Their overall frequency was 3.37%. Details are given of each malformation. Often malformations are linked to perinatal mortality (14.2% of stillbirths are malformed). There was no difference to be found between different ethnic groups. Pathological developments in previous pregnancies were not particularly frequent. Bleeding in the first trimester of pregnancy was significantly more frequent in congenital abnormalities.