What is Primary Microcephaly, MCPH1-related? Primary microcephaly, MCPH1-related, also referred to as MCPH, is a rare condition that causes individuals to be born with a small head size (microcephaly). There are several genes that can cause small head size, however, primary microcephaly, MCPH1-related, is caused by harmful genetic changes (variants) in the MCPH1 gene. Individuals with MCPH will have intellectual disability that can be mild or severe. They may also have developmental delays, including delayed speech and language skills. Motor skills may also be delayed. Other possible symptoms include shorter-than-average height and seizures. In general, individuals with MCPH do not have other significant birth defects or health issues. How common is Primary Microcephaly, MCPH1-related? The exact incidence of primary microcephaly, MCPH1-related, is unknown but is considered very rare. About 200 individuals have been reported in the literature. The condition may be more common in individuals of Pakistani descent. How is Primary Microcephaly, MCPH1-related treated? There is no cure for primary microcephaly, MCPH1-related. Early intervention and supportive therapies may assist with learning difficulties and motor delay. What is the prognosis for an individual with Primary Microcephaly, MCPH1-related? Because the condition is so rare, the estimated lifespan for individuals with MCPH is not well understood. Most individuals will have some sort of intellectual and developmental delay and may need support throughout their lives. Other names forprimary microcephaly, MCPH1-related Microcephaly primary hereditary Premature chromosome condensation syndrome References Caraffi et al., 2022, Genes (Basel)., 13(4):634, PMID: 35456440 Gregg et al., 2021, Genet Med., 23(10):1793-1806, PMID: 34285390 Kristofova et al., 2022, Cells., 11(2):275, PMID: 35053391 OMIM: Online Mendelian Inheritance in Man, OMIM [251200], 2023, https://omim.org/entry/251200