TY  - CHAP
M1  - Book, Section
TI  - Kallmann Syndrome
A1  - Ballabio, Andrea
A1  - Rugarli, Elena I.
A2  - Valle, David L.
A2  - Antonarakis, Stylianos
A2  - Ballabio, Andrea
A2  - Beaudet, Arthur L.
A2  - Mitchell, Grant A.
PY  - 2019
T2  - The Online Metabolic and Molecular Bases of Inherited Disease
AB  - Kallmann  syndrome  is  an  inherited  disorder  characterized  by  the  association  of  hypogonadotropic  hypogonadism,  due  to  gonadotropin-releasing  hormone  (GnRH)  deficiency,  with  inability  to  smell  (anosmia).  These  symptoms  are  the  result  of  a  defect  in  migration  and  targeting  of  two  specific  neuronal  subpopulations,  the  GnRH  producing  neurons  and  the  olfactory  neurons.Autosomal  dominant  (MIM  147950),  autosomal  recessive  (MIM  244200),  and  X-linked  recessive  inheritance  patterns  have  been  described  in  Kallmann  syndrome,  indicating  the  presence  of  genetic  heterogeneity.  Deletion  mapping  and  positional  cloning  efforts  in  the  distal  short  arm  of  the  X  chromosome  (Xp22.3)  led  to  the  isolation  of  the  gene  involved  in  the  X-linked  type  of  Kallmann  syndrome  (Kallmann  syndrome  protein  or  gene  symbol,  respectively  (KAL))  (MIM  308700).  Patients  with  Kallmann  syndrome  who  carry  deletions  in  the  Xp22.3  region  may  have  contiguous  gene  syndromes  and  may,  therefore,  display  the  phenotype  of  several  X-linked  disorders  associated  with  Kallmann  syndrome.In  addition  to  deletions,  several  point  mutations  in  the  KAL  gene  have  been  identified  in  patients  with  isolated  Kallmann  syndrome.The  KAL  gene  encodes  a  secreted  protein  of  680  amino  acids  that  shares  significant  similarities  with  protease  inhibitors  and  neural-cell  adhesion  molecules  (cDNA  GenBank  M97252).The  characterization  of  KAL  spatiotemporal  expression  pattern  in  human  and  chick  embryos  has  provided  important  clues  to  the  understanding  of  Kallmann  syndrome  pathogenesis.  Within  the  olfactory  system,  the  gene  is  expressed  by  the  olfactory  bulb,  which  represents  the  target  of  the  olfactory  axons.It  appears  likely  that  the  primary  defect  in  Kallmann  syndrome  is  an  abnormality  of  olfactory  system  development  affecting  axonal  targeting  and/or  synaptogenesis.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - ommbid.mhmedical.com/content.aspx?aid=1181478866
ER  -