Miguel Urioste

Proximal partial 5p trisomy resulting from a maternal (19;5) insertion

We present a case with a partial duplication 5p11-->5p13.3 resulting from a maternal ins (19,5)(p11;p11-p13.3). The diagnosis was confirmed by FISH and complement component determinations. The clinical picture was similar to those described in patients with complete duplication of the short arm and in some patients with partial 5p duplications, affecting at least band 5p13. A special significance of band 5p13 in the clinical severity of 5p duplications is discussed.

Epidemiological analysis of the schisis association in the Spanish registry of congenital malformations

Since its description by Czeizel [1981: Am J Med Genet 10:25-35], there has been general acceptance of the schisis association as a distinct entity although, to the best of our knowledge, no other epidemiological study has confirmed its existence. Here we present an epidemiologic study on schisis defects and their associations with each other in children with and without blastogenetic defects. This study demonstrates that most cases represent the dysmorphogenetic response of the primary developmental field.

Clinical/epidemiological analysis of congenital anomalies associated with diaphragmatic hernia

Several studies have been published on congenital diaphragmatic hernia (CDH), either as an isolated defect or as part of a multiple congenital anomaly (MCA) pattern. Here we present an epidemiological study designed to measure the association between CDH and a group of 17 selected congenital anomalies in an attempt to identify groups of specific defect patterns. This analysis was done using the data from the Spanish Collaborative Study of Congenital Malformations (ECEMC).

Epidemiological analysis of multi-site closure failure of neural tube in humans

Van Allen et al. [Am J Med Genet 47:723-743, 1993] proposed that there is multi-site initiation of neural tube closure in humans, and that neural tube defects (NTD) represent the failure of one or more of 5 closure sites. We have studied from an epidemiologic perspective 774 liveborn infants with NTD by site of lesion following the multi-site classification proposed by Van Allen et al. [1993]. As predicted by these authors, we could classify all the cases with NTD by the multisite closure model. We have also estimated the prevalence of each failure closure site. This analysis indicates that not all the sites are affected with similar frequency.

Tetrasomy 5p mosaicism due to an extra i(5p) in a severely affected girl

We present a case of mosaic 5p tetrasomy. The mosaicism 46,XX/47,XX,+i(5p) was found at different ratios in blood lymphocytes, skin fibroblasts, and chondrocytes. The origin of the extra isochromosome was confirmed by FISH. The clinical picture corresponds to that described in trisomy 5p patients, although it was more severe than the two previously reported cases of mosaic 5p tetrasomy. No correlation between clinical severity and proportion of tetrasomic cells in blood or fibroblasts was found in these cases.

Severe congenital limb deficiencies, vertebral hypersegmentation, absent thymus and mirror polydactyly: a defect expression of a developmental control gene?

We describe two unrelated patients with a complex malformation pattern that may be a candidate for a developmental gene disorder. These two patients had severe, symmetrical upper and lower limb deficiencies, vertebral hypersegmentation, and duodenal atresia. Patient 1 also had mirror-image polydactyly of his feet; patient 2 was athymic. The concurrence in two unrelated patients of additional vertebrae with severe anomalies in limb development, including a symmetrical deficiency of the four limbs and either mirror-image duplication of some toes (only in patient 1) or absence of the thymus (only in patient 2), represents an early alteration in body-plan organization. Since limb development, thymus development and segmentation are possibly under the control of homeobox genes in the human embryo, it seems reasonable that the malformations observed in these two patients resulted from a defect of a gene controlling developmental pattern formation, possibly a homeobox gene or a paired-box gene. Severe limb deficiencies have been reported in other well-known genetic entities, such as Roberts syndrome, Baller-Gerold syndrome, X-linked amelia, and DK-phocomelia syndrome. However, since the specific pattern of anomalies observed in these patients makes the diagnosis of some of the abovementioned disorders unlikely, we conclude that our patients have a previously undescribed disorder.

An unusual variant of chromosome 16

SummaryTwo new cases of an unusual chromosome 1y variant, 16p+, in non-related normal carriers are reported.

Anencephaly and faciocranioschisis: Evidence of complete failure of closure 3 of the neural tube in humans

We report on a patient with median cleft of face and anencephaly as apparent consequence of delayed closure of the most rostral end of the neural tube. No other structural anomalies were found. To our knowledge, this child represents the first description of an isolated and complete failure of closure 3 of the neural tube and supports the hypothesis of a multi-site model of neural tube closure in humans.

Giant-cell chondrodysplasia in a male infant with clinical and radiological findings resembling the Piepkorn type of lethal osteochondrodysplasia.

We report on a patient whose clinical, radiologic, and histopathologic findings are compatible with the Piepkorn type of lethal short-limb osteochondrodysplasia, but who also showed multinucleated giant chondrocytes in cartilage. Multinucleated giant cells are an unusual finding in osteochondrodysplasias, having been reported in atelosteogenesis type I and boomerang dysplasia. This uncommon histopathologic finding and the clinical and radiographic findings strongly support the diagnosis of boomerang dysplasia in the present patient. Our patient supports the previously suggested existence of an entity including atelosteogenesis and boomerang dysplasia. If this is so, the current patient and that described by Piepkorn et al. [1977: Teratology 16:345-350] could represent the most severe clinical expression of that condition.