The main clinical features of individuals with a Noonan syndrome-associated LZTR1 variant are coarse facial features, including macrocephaly, hypertelorism with ptosis, and low-set ears; congenital heart disease; delayed growth and short stature; variable levels of intellectual disability. Musculoskeletal defects, such as pectus excavatum or pectus carinatum, or a webbed neck may also be present.
The main clinical features of individuals with a schwannomatosis-associated LZTR1 variant are the development of multiple spinal and/or peripheral schwannoma tumours. Approximately 5% of people with a schwannomatosis-associated LZTR1 variant will develop a vestibular schwannoma (VS), which can complicate diagnosis, as VS is more commonly associated with a germline NF2 variant.
LZTR1