Documentation of anomalies not previously described in Fryns syndrome.

We report on a case of Fryns syndrome with microcephaly, multiple facial anomalies, hypoplasia of distal phalanges, diaphragmatic defect with a thin, translucent diaphragm, microphthalmia (right), anophthalmia (left), and multiple midline developmental defects including gastroschisis, central nervous system defects including left arrhinencephaly and cerebellar hypoplasia, midline cleft of the upper lip, alveolar ridge and maxillary bone, and cleft nose with bilateral choanal atresia. These defects add to our knowledge of the phenotype of Fryns syndrome.

Megacystis-microcolon-intestinal hypoperistalsis syndrome and aganglionosis in trisomy 18.

Ultrasonography at 23 weeks of gestation documented the presence of megacystis with horseshoe kidney, microcolon, intestinal malrotation, and decreased amniotic fluid volume. After pregnancy termination, an autopsy was performed. The external phenotype was diagnostic of the trisomy 18 syndrome confirmed by chromosome examination. The fetus also had a massively distended bladder with parchment-thin wall, microcolon, intestinal malrotation but no urethral obstruction or hydronephrosis. No ganglion cells were present in the colon or bladder. This has not been mentioned in other reported cases and, therefore, suggests pathogenic heterogeneity. The megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare autosomal recessive condition of unknown pathogenesis whose genes map to 15q24. Thus, its previously undescribed presence in trisomy 18 further suggests etiologic heterogeneity.

Evidence for the "midline" hypothesis in associated defects of laterality formation and multiple midline anomalies.

A male infant was liveborn at 38 weeks of gestation to a G4P1AB2, 22-year-old, mother. Polyhydramnios and multiple congenital anomalies were noted by ultrasonography; the infant died 5 min after birth. At autopsy, the infant had multiple defects of blastogenesis including midline anomalies with asplenia and abnormalities of laterality formation. The laterality defects were unusual in that they combined asplenia with hypoplastic, symmetrically unilobate lungs and bilateral hyparterial bronchi more consistent with polysplenia, abdominal situs inversus with midline stomach, symmetric liver, and left gallbladder. No intracardiac abnormalities were present, but there was azygous continuation of the inferior vena cava. Additional multiple midline defects included bronchoesophageal fistula, duodenal atresia, absence of posterior leaf of diaphragm; horseshoe adrenal gland; microcephaly; Dandy-Walker anomaly with agenesis of cerebellar vermis and occipital encephalocele; holoprosencephaly with orbital encephalocele, midline defect of the orbital plate of the skull, bilateral anophthalmia, double proboscis with bilateral choanal atresia, midline upper lip and palatal cleft; single-lobed thyroid; hypoplastic external genitalia with midline cleft of scrotum, long tapering fingers, and defects of the cranium at the sites of orbital and occipital encephaloceles. Defects of laterality frequently are associated with other complex midline anomalies, which both result from a disturbance of pattern formation during blastogenesis, i.e., the induction of the progenitor fields. The latter are the result of the establishment of upstream expression domains of growth and transcription factors and other morphogens. Many of these and other genetic systems, expressed asymmetrically around the midline, are responsible for laterality formation and are the result of upstream and subsequent downstream gene expression cascades through the expression of genes such as HOX genes; bFGF; transforming growth factor beta/activins/BMP4; WNT-1,8; and SHH.

Bronchopulmonary-foregut malformations: a continuum of paracrine hamartomas?

The bronchopulmonary-foregut malformations (BPFM) are usually sporadic, solitary cystic hamartomas involving conducting airways, arteries, venous drainage, and lung parenchyma. Transitional, compound hamartomas exist, and only their morphology is well-known. Between 1984-1994 we encountered and studied 10 unrelated patients and a stillborn infant with BPFM (out of 24,000 families). Ten were diagnosed in utero and one at birth as having congenital cystic adenomatoid malformation of the lung (CCAML). Postnatally, two diagnoses (20%) were corrected to bronchogenic cyst (BC) and diaphragmatic hernia, respectively. Bilateral lung involvement was present in 1 patient, and in 2 there was a considerable macroscopic regression of the hamartoma. Histologic studies of the six resected CCAML confirmed the diagnosis and implied dysregulated paracrine growth with its cellular and extracellular growth factors, protooncogenes, oncogenes, cytokines, cell-adhesive molecules, and receptors of these regulatory peptides, and their complex interactions as developmental morphogens in time and space.