- Typified by somatic mosaicism (HP:0001442): Description of conditions in which affected individuals typically display somatic mosaicism, i.e., genetically distinct populations of somatic cells in a given organism caused by DNA mutations, epigenetic alterations of DNA, chromosomal abnormalities or the spontaneous reversion of inherited mutations. In many conditions typified by somatic mosaicism, constitutive mutation is lethal and cases are exclusively or predominantly mosaic. Evidence: PCS. Frequency: 1/1. (PMID:32170967)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/1. (PMID:32170967)
- Hypertrichosis (HP:0000998): Hypertrichosis is increased hair growth that is abnormal in quantity or location. Evidence: PCS. Frequency: 1/1. (PMID:32170967)
- Hamartoma (HP:0010566): A disordered proliferation of mature tissues that is native to the site of origin, e.g., exostoses, nevi and soft tissue hamartomas. Although most hamartomas are benign, some histologic subtypes, e.g., neuromuscular hamartoma, may proliferate aggressively such as mesenchymal cystic hamartoma, Sclerosing epithelial hamartoma, Sclerosing metanephric hamartoma. Evidence: PCS. Frequency: 1/1. (PMID:32170967)
- Hemihypertrophy (HP:0001528): Overgrowth of only one side of the body. Evidence: PCS. Frequency: 1/1. (PMID:32170967)
These phenotypes are associated with the disease congenital smooth muscle hamartoma, with or without hemihypertrophy (OMIM:620470).