Thanatophoric dysplasia type II with encephalocele and semilobar holoprosencephaly: Insights into its pathogenesis.

摘要: Thanatophoric dysplasia (TD) is a lethal form of short-limb skeletal that associated with macrocephaly, and variably cloverleaf skull. Two types TD are clinically recognized, TD1 TD2, mainly distinguished by their radiographic characteristics. The differences between the two principally observed in femur, which appears curved TD1, while it remains straight but proximal medial spike less severe overall affectation TD2. Both caused mutations different functional domains FGFR3 gene. However, whereas several cause K650E mutation involving change lysine to glutamic acid ("Lys650Glu") has been found all TD2 cases date. Here we describe newborn infant brain defects have either infrequently (encephalocele) or not hitherto described (holoprosencephaly). Based on recent studies, consider encephaloceles be pseudoencephaloceles, since they secondary intracranial pressure generated hydrocephaly cranial structural anomalies. Finally, analyze mechanisms holoprosencephaly case here, include concise review current understanding how FGFs receptors expressed rostral signaling center (particularly Fgf8). In addition, evaluated observations FGF ligands (including FGFR3) act concert organize whole telencephalon activity, rather than independently patterning areas.