An elevation of the level of the enzyme creatine kinase (also known as creatine phosphokinase (CK; EC 2.7.3.2) in the blood. CK levels can be elevated in a number of clinical disorders such as myocardial infarction, rhabdomyolysis, and muscular dystrophy.

Typical Greig cephalopolysyndactyly syndrome (GCPS) is characterized by macrocephaly, widely spaced eyes associated with increased interpupillary distance, preaxial polydactyly with or without postaxial polydactyly, and cutaneous syndactyly. Developmental delay, intellectual disability, or seizures appear to be uncommon manifestations (~<10%) of GCPS and may be more common in individuals with large (>300-kb) deletions that encompass GLI3. Approximately 20% of individuals with GCPS have hypoplasia or agenesis of the corpus callosum.

Autosomal recessive limb-girdle muscular dystrophy-29 (LGMDR29) is a neuromuscular disorder characterized by onset of muscle weakness predominantly affecting the proximal lower limbs, although upper limb involvement also occurs. The disorder, which causes walking difficulties, is progressive and may result in loss of ambulation. Additional features include joint contractures, spinal abnormalities, and significant restrictive ventilatory dysfunction. Muscle biopsy shows dystrophic and myofibrillar changes, and serum creatine kinase is increased. Rare individuals have been reported to have central nervous system involvement, including cataracts, developmental delay, and brain imaging abnormalities (Nashabat et al., 2024 and Iruzubieta et al., 2024). For a discussion of genetic heterogeneity of autosomal recessive limb- girdle muscular dystrophy, see LGMDR1 (253600).