Early prenatal sonographic diagnosis of neuropathic arthrogryposis multiplex congenita with osseous heterotopia

A prenatal diagnosis of arthrogryposis multiplex congenita (AMC) has been carried out on a 19-week-old fetus by means of echography. The ultrasonographic characteristics were unnatural position of the four limbs associated with articular anomalies together with absence of active fetal movements. A therapeutic interruption of pregnancy was performed and the diagnosis was confirmed. At autopsy, architectural disorder of the motor neurons of the anterior medullary horn revealed a neuropathic pathogenesis of the arthrogryposis. Moreover, at the lumbar level the spinal cord was progressively replaced by heterotopic bony tissue which caused a more severe deformity of the lower limbs compared with the upper. The aspects of anatomo-pathological, genetic, and differential diagnosis are discussed showing the precocity of the prenatal diagnosis and the peculiarity of the aetiology of our case.     

Prenatal diagnosis of zellweger's syndrome by chorionic villus sampling-and a caveat

At 7·5 weeks gestation, two small chorionic villous biopsies were obtained from a woman at risk for Zellweger's cerebro-hepato-renal syndrome, and were separately established in culture. After 3 weeks, dihydroxyacetone phosphate acyltransferase (DHAP-AT) activity was measured in both cultures. The enzyme was markedly deficient in one cell strain and this was subsequently shown to have a male karyotype. However, the second culture had normal enzyme activity and a female karyotype. The pregnancy was terminated at 11·5 weeks gestation, and follow-up studies on fetal tissues confirmed a male fetus with markedly deficient DHAP-AT activity.     

A case of partial sirenomelia and possible vitamin A teratogenesis

Prenatal echographical findings of a partial sirenomelic fetus are described. An attempt was made to terminate pregnancy by administration of prostaglandin F₂a, but uterine rupture occurred. The teratogenic role of vitamin A ingested by the mother in the penconceptional period is discussed.     

Amniotic band syndrome in second trimester associated with fetal malformations

The Possibility of severe fetal malformations, including neural tube defects, secondary to early amniotic rupture followed by formation of fibrous bands (amniotic band syndrome) is a well-known entitity. The fact that these pregnancies are usually uneventful makes prenatal diagnosis difficult, but routine determination of serum alphafetoprotein, followed by ultrasound scanning, may detect some of the malformations. We present a case, where detection of a neural tube defect led to induced second trimester abortion of a fetus severely affected by this syndrome. There appeared to be a causal relationship between maternal trauma and the amniotic rupture.     

Prenatal ultrasound diagnosis of macroglossia in the Wiedemann-Beckwith syndrome

We report the ultrasound prenatal diagnosis at the 30th week of macroglossia in two sibs with the Wiedemann-Beekwith syndrome; the syndrome was also present in their mother. A study of high resolution chromosomes did not show any anomaly.     

hCG,AFP, and uE3 patterns in the 14–20th weeks of Down's syndrome pregnancies

A marked gestational-age-dependent variation in the 15-20th week pattern of human chorionic gonadotropin concentrations in Down's syndrome (DS) pregnancies is described and its weight in DS screening is discussed.     

Fetal blood sampling demonstrating chimerism in monozygotic twins discordant for sex and tissue karyotype (46,XY and 45,X)

Fetal blood sampling has been used in the genetic work-up of twin gestations for rapid karotyping. We present a case of twins which on ultrasound evaluation revealed hydrops fetalis in one twin and a normal second twin. Fetal blood sampling revealed the presence of mosaicism for 46,XY/45,X in both twins. HLA antigen testing showed the twins to be identical. The patient elected pregnancy termination. Blood chromosomal analysis after delivery revealed both twins to have 46,XY/45,X mosaicism, but the twin with signs of hydrops fetalis had tissue chromosomes of 45,X and the normal twin had tissue chromosomes of 46,XY. Amniotic fluid chromosomal analysis revealed 46,XY in twin A and 45,X in twin B. This represents a case of identical (monozygotic) twins with sex discordance. In this case, there was the probable occurrence of post-zygotic chromosomal non-disjunction leading to the discordancy of the sex in this set of twins. With the presence of vascular communication in monozygotic twins, there is the possibility of exchange of blood in monozygotic twins and the result of blood chimerism in twins.     

Prenatal diagnosis of recurrent Larsen syndrome: Further definition of a lethal variant

Larsen syndrome is characterized by multiple congenital joint dislocations and flattened facies. Some cases have been familial, with both autosomal dominant and recessive patterns of inheritance. Reports of a form of Larsen syndrome, lethal in the neonatal period, are reviewed. We present a family in which recurrence of the syndrome was diagnosed prenatally, but a lethal outcome again resulted despite preparation for anticipated perinatal complications. Because of the wide clinical variation and the lack of a known metabolic defect, delineation between the various forms of Larsen syndrome is difficult. While the lethal variant appears to be a combination of the Larsen phenotype and pulmonary hypoplasia, other features noted in the lethal cases, such as abnormal palmar creases and laryngotracheomalacia, are also seen in patients with Larsen syndrome who survive.     

Prenatal diagnosis of xeroderma pigmentosum and cockayne syndrome

In a study of fetal cells from a series of 12 pregnancies in ten families at risk for the ultraviolet light-sensitive, DNA repair-deficient diseases xeroderma pigmentosum (XP) and Cockayne syndrome (CS), we detected one XP and two CS homozygote fetuses. The diagnoses were confirmed by analysis of fetal skin fibroblasts or second amniotic samples after termination of the pregnancies. The measurement of ultraviolet light sensitivity and DNA repair depended on properties common to the seven excision repair-deficient XP complementation groups (A-G) and the two CS complementation groups (A, B). No XP variant families were included in the study, because the variant requires different testing techniques. Reliable and rapid diagnosis proved possible in all but one of the 12 pregnancies, supporting the use of these methods until the spectrum of mutations in the various XP and CS genes of the U. S. population is fully characterized and a DNA sequence-based diagnostic procedure becomes available.