CDKL5 and scoliosis: Nevertheless, the improvement of the clinical overview of CDD in the past few years has defined a more detailed phenotypic spectrum; this includes very common alterations in peripheral organ and tissue function, such as gastrointestinal problems, irregular breathing, hypotonia, and scoliosis [32], suggesting that CDKL5 deficiency compromises not only CNS function but also that of other organs/tissues.