"Heterotaxy" is the term for a form of genetic defect where major organs are not in the proper location in the body. While not unheard of in Flats, the defect has been extinguished in Splicers and better though technically some lines of morphs may be heterotaxic compared to standard transhuman or other "source" genes for design purposes. This idea of relocating organs for specific purposes can be applied to other things, such as implants, which led to the exotic development of the Heterotaxy Cyberbrain.
Heterotaxy Cyberbrain: In short, this implant/enhancement is applied to a morph which already has a Cyberbrain and relocates the cyberbrain to another location inside the body besides the normal one. For humanoid morphs this is typically the head, and the relocation may be to the body - but can be even so exotic as to be in a limb. The dimensions of the cyberbrain do not need to be exactly the same, but the relocated area must be able to hold a sufficiently strong computer to run the cyberbrain software. In place of the normal cyberbrain routing hardware is usually installed to make sure sensory input and command output is processed through the rest of the body correctly and prevent undue disorientation to the Ego. Sleeving into a morph with a Heterotaxy Cyberbrain is slightly unusual, and can be difficult, imposing a -10 penalty on Resleeving tests. This implant can only be applied to morphs with a Cyberbrain. [High]
The primary purpose of the Heterotaxy Cyberbrain is the obvious - a relocated brain makes it difficult to permanently disable a morph via cranial damage. While there are severe penalties due to problems with senses and coordination (i/e Wounds) for taking head trauma, a morph is unlikely to be stopped simply by suffering blows to the head - and instead suffers similar effects when struck in the area where the Cyberbrain has been relocated. It is often combined with the Possum Cache (p. 198 Transhuman) in order to better "play dead". Barring expensive implant masking, The Heterotaxy Cyberbrain is incredibly easy to detect if one knows what to look for, however. The cranial area is much less dense and will obviously lack a proper brain to scan ("empty-head" or "air-head" is a common nickname for HC users) and the increased mass and electrical activity of the relocated cyberbrain can be very obvious to many types of scanners. The users of the Heterotaxy Cyberbrain tend to be eccentric or paranoid.