Bilateral frontoparietal polymicrogyria is a genetic disorder with autosomal recessive inheritance that causes a cortical malformation. Our brain has folds in the cortex to increase surface area called gyri and patients with polymicrogyri have an increase number of folds and smaller folds than usual. Polymicrogyria is defined as a cerebral malformation of cortical development in which the normal gyral pattern of the surface of the brain is replaced by an excessive number of small, fused gyri separated by shallow sulci and abnormal cortical lamination. From ongoing research, mutation in GPR56, a member of the adhesion G protein-coupled receptor (GPCR) family, results in BFPP. These mutations are located in different regions of the protein without any evidence of a relationship between the position of the mutation and phenotypic severity. It is also found that GPR56 plays a role in cortical pattering. Presentation
Symptoms: Developmental delay, Psychomotor delay, Mental retardation - moderate to severe, Exaggerated reflexes and Seizures (epilepsy)

Associated conditions
BFPP is a cobblestone-like cortical malformation of the brain. Disruptions of cerebral cortical development due to abnormal neuronal migration and positioning usually lead to cortical disorders, which includes cobblestone lissencephaly. Cobblestone lissencephaly is typically seen in three different human congenital muscular dystrophy syndromes:  Fukuyama congenital muscular dystrophy, Walker-Warburg syndrome, and muscle-eye-brain disease. In cobblestone lissencephaly, the brain surface actually has a bumpy contour caused by the presence of collections of misplaced neurons and glial cells that have migrated beyond the normal surface boundaries of the brain.
Pachygyria and polymicrogyria may look similar on low-resolution neuroimaging such as CT because the cortical thickness can appear to be increased and the gyri can appear to be broad and smooth in both conditions. This is why higher resolution neuroimaging, such as an MRI, is necessary for proper diagnosis. Genetics
The GPR56 is grouped in the B family of GPCRs. This GPCR group have long N termini characterized by an extracellular “cysteine box” and hydrophilic, potentially mucin-rich. The cysteine box contains four conserved cysteines and two tryptophans arranged in a specific fashion (C-x2-W-x6-16-W-x4-C-x10-22-C-x-C) just before the first transmembrane domain and serves as a cleavage site in some members of this group of G protein–coupled receptors. Although, the molecular and cellular mechanisms of how GPR56 regulates brain development remain largely unknown. These types of receptors play an essential role in biological processes including embryonic development, central nervous system (CNS), immune system, and tumorigenesis. Mode of inheritance
Parents of a proband

The parents of an affected individual are obligate heterozygotes and therefore carry one mutant allele. Heterozygotes (carriers) are asymptomatic.Sibs of a proband

At conception, each sibling of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Once an at-risk sibling is known to be unaffected, the risk of his/her being a carrier is 2/3. Heterozygotes (carriers) are asymptomatic.Offspring of a proband

Offspring of a proband are obligate heterozygotes and will therefore carry one mutant allele.