open neural tube defects. Nevertheless other central nervous system lesionssuch as arachnoid cysts may be associated and thus abnormal PAPP-A levelscould possibly alert detailed prenatal ultrasound examination of centralnervous system anatomy.

doi:10.1016/j.earlhumdev.2008.09.300

Abstract UENPS.285Sindrome di down con disordine mieloide e insufficienza epaticafulminante/down myeloid disorder with a fatal fulminant hepatic failure

Bruno Cardoso⁎, Maria Oliveira, Juliette Dupont,E. Silva Artur Costa, Margarida AlbuquerqueSanta Maria Hospital, Lisbon, Portugal

Background and aim

Down syndrome (DS) is one of the commonest congenital disordersaffecting 1/800–1000 live births.

Transient leukaemia, also known as transient myeloproliferative disorder(TMD) or transient abnormal myelopoiesis, is a form of leukaemia that almostexclusively affects newborns with DS. The majority of newborns are asynto-matic,with spontaneous resolutionof thedisorder by two to 3months, althoughsome develop severe disease with fulminant hepatic failure secondary tofibrosis. The liver pathology is likely to reflect hepatic infiltration and secondaryfibrosis with abnormal fetal haemopoietic cells. Thus, TMD is certainly initiatedin fetal life when the liver is a haemopoietic organ.

The investigation of the molecular and cellular biology of these disordersdiscovered that virtually all cases of TMD and acute megakaryocyticleukaemia are characterised by a mutation in the key megakaryocyte-erythroid transcription factor GATA1. There is evidence that these GATA 1mutations are acquired in utero.

Materials and methods

We report a neonate with DS and myelodysplasia associated with a fatalfulminant hepatic failure secondary to fibrosis. Tests for bacterial and viralinfection (TORCH group) and metabolic diseases including haemochroma-tosis were normal. Biliary tree abnormalities were ruled out by echographyand cyntigraphy. She died with 23 days of life.

The diagnosis was confirmed by the findings of portal with ductalproliferation, colestasis, moderade siderosis and fibrosis with detection ofcytokines like TGFß, PDGF and PF4 in the liver; the bone marrow aspirateshowed a reduced number of cells with increase of myeloblasts (12%) andmyelodysplastic phase with criteria of SMD/AREB 2 (OMS classification).

Results

The Gata1 mutational analysis was done by wave (high performanceliquid chromatography), the wave suggested a mutant clone in exon 3.1 ofgata1, but unfortunately confirmation by genomic sequencing was notpossible.

Conclusions

Keywords: Down syndrome, Myeloid disorder, Fulminant hepatic failure,Gata1 mutational

doi:10.1016/j.earlhumdev.2008.09.301

Abstract UENPS.286Hipo/acalvaria primaria in un neonato con una buona evoluzione/primary hypo/acalvaria in a term newborn with a good outcome

Bruno Cardoso⁎, Susana Castanhinha, Margarida Albuquerque,Graca Oliveira, Juliet DupontSanta Maria Hospital, Lisboa, Portugal

Background and aim

Primary hypo/acalvaria is a rare congenital postneurolation anomaly ofunknown pathogenesis. The flat bones of the cranial vault (calvarial bones)are absent but there is a normal development of chondrocranium, presenceof cerebral hemispheres, and intact overlying skin that protects the brain.

The term primary hypo/acalvaria is used to distinguish it from cases thathave other causes, such as amniotic band syndrome, neural tube defects andtherapeutic use of angiotensin converting enzyme inhibitors duringpregnancy. It has been described as a fatal anomaly but there are somereports of living children with disabilities.

Materials and methods

Our report is about a living case of primary hypo/acalvaria with noprenatal diagnosis or cerebral anomaly. This case study looks at thefavourable development milestones and progressive growth of the skullbones at 7 months of age.

Results

As the absence or severe hypoplasia of the parietal bones at birth isassociated to MSX2 and ALX4 mutations, the molecular test for these geneswere performed and show no mutations.

Conclusions

Keywords: Primary acalvaria, Skull defect, Congenital malformation

doi:10.1016/j.earlhumdev.2008.09.302

Abstract UENPS.287Anatomical study on pulmonary arteries at fetal age

Nadia Schmidt⁎, Gabriela Corina Zaharie, Florin Stamatian, Tunde KovacsUniversity of Medicine and Pharmacy Iuliu Hatieganu, Cluj Napoca, Romania

Background and aim

Interactions between airways and blood vessels are critical for normallung development. The parallel processes of alveolarization of the distal lungsaccules and development of the alveolar capillary bed are just beginning at<28 weeks of gestation.

Our study focuses on morphology and size of right and left pulmonaryarteries (RPA, LPA).

Materials and methods

Three subjects (abortion of maternal cause), two female and one malewith gestational age between 24 and 27 weeks.

The injection of colored nitrolac in the right ventricle, dissection (andphotographed under the operative microscope) of RPA and LPA, includingtheir segmental intrapulmonary branches, histological sections stained withhematoxylin eosine, Masson's trichrome and orceine were performed andthe external diameter of the RPA and LPA were measured.

Results

The RPA and LPA segmental branches are higher as number at 24–27 fetalweeks as in the adult.

The structure of the arterial wall differs according to the position of theartery within the lung.

Conclusions

The size values of RPA and LPA assessed can be useful in pulmonaryultrasound exams. The structure of arteries on the lung sections explainpulmonary hypertension at the neonates borned <28 weeks gestation.

doi:10.1016/j.earlhumdev.2008.09.303

Abstracts S117