Question: What is (are) 9q22.3 microdeletion ?
Answer: 9q22.3 microdeletion is a chromosomal change in which a small piece of chromosome 9 is deleted in each cell. The deletion occurs on the long (q) arm of the chromosome in a region designated q22.3. This chromosomal change is associated with delayed development, intellectual disability, certain physical abnormalities, and the characteristic features of a genetic condition called Gorlin syndrome. Many individuals with a 9q22.3 microdeletion have delayed development, particularly affecting the development of motor skills such as sitting, standing, and walking. In some people, the delays are temporary and improve in childhood. More severely affected individuals have permanent developmental disabilities along with intellectual impairment and learning problems. Rarely, seizures have been reported in people with a 9q22.3 microdeletion. About 20 percent of people with a 9q22.3 microdeletion experience overgrowth (macrosomia), which results in increased height and weight compared to unaffected peers. The macrosomia often begins before birth and continues into childhood. Other physical changes that can be associated with a 9q22.3 microdeletion include the premature fusion of certain bones in the skull (metopic craniosynostosis) and a buildup of fluid in the brain (hydrocephalus). Affected individuals can also have distinctive facial features such as a prominent forehead with vertical skin creases, upward- or downward-slanting eyes, a short nose, and a long space between the nose and upper lip (philtrum). 9q22.3 microdeletions also cause the characteristic features of Gorlin syndrome (also known as nevoid basal cell carcinoma syndrome). This genetic condition affects many areas of the body and increases the risk of developing various cancerous and noncancerous tumors. In people with Gorlin syndrome, the type of cancer diagnosed most often is basal cell carcinoma, which is the most common form of skin cancer. Most people with this condition also develop noncancerous (benign) tumors of the jaw, called keratocystic odontogenic tumors, which can cause facial swelling and tooth displacement. Other types of tumors that occur more often in people with Gorlin syndrome include a form of childhood brain cancer called a medulloblastoma and a type of benign tumor called a fibroma that occurs in the heart or in a woman's ovaries. Other features of Gorlin syndrome include small depressions (pits) in the skin of the palms of the hands and soles of the feet; an unusually large head size (macrocephaly) with a prominent forehead; and skeletal abnormalities involving the spine, ribs, or skull.
Source: GHR

Question: Is 9q22.3 microdeletion inherited ?
Answer: 9q22.3 microdeletions are inherited in an autosomal dominant pattern, which means that missing genetic material from one of the two copies of chromosome 9 in each cell is sufficient to cause delayed development, intellectual disability, and the features of Gorlin syndrome. A 9q22.3 microdeletion most often occurs in people whose parents do not carry the chromosomal change. In these cases, the deletion occurs as a random (de novo) event during the formation of reproductive cells (eggs or sperm) in a parent or in early embryonic development. De novo chromosomal changes occur in people with no history of the disorder in their family. Less commonly, individuals with a 9q22.3 microdeletion inherit the chromosomal change from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which a segment of chromosome 9 has traded places with a segment of another chromosome. No genetic material is gained or lost in a balanced translocation, so these chromosomal changes usually do not cause any health problems. However, translocations can become unbalanced as they are passed to the next generation. People who inherit a 9q22.3 microdeletion receive an unbalanced translocation that deletes genetic material from one copy of the q22.3 region of chromosome 9 in each cell. Having one missing copy of the PTCH1 gene in each cell is enough to cause the features of Gorlin syndrome that are present early in life, including macrocephaly and skeletal abnormalities. For basal cell carcinomas and other tumors to develop, a mutation in the other copy of the PTCH1 gene must also occur in certain cells during the person's lifetime. Most people who are born with one missing copy of the PTCH1 gene eventually acquire a mutation in the other copy of the gene in some cells and consequently develop various types of tumors.
Source: GHR

Question: What are the treatments for 9q22.3 microdeletion ?
Answer: These resources address the diagnosis or management of 9q22.3 microdeletion: - Gene Review: Gene Review: 9q22.3 Microdeletion - Gene Review: Gene Review: Nevoid Basal Cell Carcinoma Syndrome - Genetic Testing Registry: Gorlin syndrome - MedlinePlus Encyclopedia: Basal Cell Nevus Syndrome These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Source: GHR