W orldwide, puberty is recognized by various cultures and celebrated as a rite of passage into adulthood. The methodical drumbeat of these religious and social ceremonies foreshadows the rhythm of reproduction that, in many ways, marks the final stage of development. Despite its social and physiological significance, including perpetuation of the species, the pathways that regulate the onset of...

Kallmann syndrome and normosmic isolated hypogonadotropic hypogonadism (IHH) are developmental disorders characterized by hypogonadotropic hypogonadism that, in the former case, is coupled to loss of the sense of smell. Linkage analyses, deletion mapping and candidate gene approaches uncovered several loci in the pathogenetic mechanism of these diseases (Figure 1). However, loss-of-function mut...

Kallmann syndrome (KS) combines hypogonadotropic hypogonadism and anosmia. Anosmia is related to the absence or hypoplasia of the olfactory bulbs and tracts. Hypogonadism is due to gonadotropin-releasing hormone (GnRH) deficiency, which presumably results from a failure of the embryonic migration of neuroendocrine GnRH cells from the olfactory epithelium to the forebrain. This failure could be ...

Terminal or interstitial deletions of Xp (Xp22.2→Xpter) in males have been recognized as a cause of contiguous gene syndromes showing variable association of apparently unrelated clinical manifestations such as Leri-Weill dyschondrosteosis (SHOX), chondrodysplasia punctata (CDPX1), mental retardation (NLGN4), ichthyosis (STS), Kallmann syndrome (KAL1), and ocular albinism (GPR143). Here we pres...

Kallmann syndrome (KS) is an inherited developmental disorder defined as the association of hypogonadotropic hypogonadism and anosmia or hyposmia. KS has been shown to be a genetically heterogeneous disease with different modes of inheritance. However, variants in any of the causative genes identified so far are only found in approximately one third of KS patients, thus indicating that other ge...

Kallmann Syndrome (KS) is a genetic disease of embryonic development which is characterized by the association of hypogonadotropic hypogonadism (HH) due to a deficit of the gonadotropin-releasing hormone (GnRH) and a hypo/anosmia (including a hypoplasia of the nasal sulcus and agenesis of the olfactory bulbs). Even though it is a genotypically and phenotypically heterogeneous clinical disease, ...

In this chapter, we study algebraic groups, especially nonsplit reductive groups, over arbitrary fields. The algebraic groups over a field k that become isomorphic to a fixed algebraic group over kal are classified by a certain cohomology group. In the first section, we explain this, and discuss what is known about the cohomology groups. Over an algebraically closed field, the classical semisim...

BACKGROUND In recent years, several genes were found to be involved in the process of epididymo-testicular descent, the most frequently cited ones include INSL3, HOXA10, GNRHR, and KAL1. In this study, we analyzed the differences in gene expression profiles between cryptorchid and descended testes. In particular, we analyzed expression of all recently published genes known to be associated with...

BACKGROUND Contiguous gene syndrome (CGS) is characterized by a series of clinical features resulting from interstitial or terminal deletions of various adjacent genes. Several important genes have been identified in the Xp22.3 region to be responsible for genetically heterogeneous diseases. In this study, fluorescence in situ hybridization (FISH) methods were used to detect the extent of gene ...