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We report a new and rare case of recurrent anencephaly in a family with no other apparent abnormalities. The karyotypes of the family and all affected subjects were normal. Thorough mutational analyses of VANGL1 of chromosome 1p13.1 and FOXN1 of chromosome 17q11-q12, genes that are associated with phenotypes of the anencephaly spectrum, unfortunately did not disclose any DNA variations in an affected fetus of this family. The etiology of recurrent anencephaly in this family is therefore due to mutations in genes yet to be discovered, perhaps of the planar cell polarity pathway, or to possible environmental gestational factors during development. [ABSTRACT FROM AUTHOR]

We report a new case of a fetus with holoprosencephaly-polydactyly syndrome, also known as pseudo-trisomy 13 syndrome, and no other apparent abnormalities except for septal agenesis of the left lung. The fetal karyotype was normal. Mutational analysis of five genes (SHH, SIX3, TGIF, ZIC2, and GLI3), which are major genes associated with holoprosencephaly, did not disclose any mutational findings. We therefore propose that the abnormalities of our fetus support the demarcation of this syndrome as an autonomous phenotype. Specific diagnostic criteria for holoprosencephaly-polydactyly syndrome need to be complemented by the absence of mutations in the major holoprosencephaly genes. [ABSTRACT FROM AUTHOR]

Abstract: Agnathia-otocephaly, a rare, sporadic and lethal malformation, is characterized by microstomia (small mouth), aglossia (absence of the tongue), agnathia (absence of the lower jaw) and abnormally positioned ears. It is a principal anomaly derived from the first pharyngeal arch as a consequence of failed mesenchymal migration of the maxillary prominence and atrophy in the development of the mandibular prominences. Unfortunately, these patients have poor prognoses and may succumb to death shortly after birth due to respiratory problems if appropriate airway management is not implemented. Difficulties persist in the prenatal diagnosis of agnathia-otocephalic patients. However, two- and three-dimensional ultrasonography, computed tomography and magnetic resonance imaging technologies now offer significant improvements in refining the resolution of distinctive facial anomalies. This complex disorder can be attributed to both genetic and teratogenic causes, in addition to other unidentifiable factors. Furthermore, studies in model organisms, in particular mice, have unraveled potential genetic pathways that may contribute to the etiology. This article highlights current perspectives on agnathia-otocephaly with a focus on the etiological causes and issues concerning prenatal diagnosis, differential diagnosis, prognosis and genetic counseling. Finally, studies using animal models especially genetically engineered mice are described to comprehend the molecular genetic interactions that may occur during the genesis of this intriguing craniofacial birth defect. [ABSTRACT FROM AUTHOR]