Multiple signs can be observed with relative
frequencies: head anomalies (macrocephaly, scaphocephaly, down-slanting palpebral
fissures, strabismus, amblyopia, prominent Schwalbe lines, hypertelorism,
exotropia, pseudopapilledema tongue, polyps, high-arched palate), chest anomalies (pectus
excavatum, supernumerary nipples), genital anomalies (enlarged penis, enlarged testis),
abdominal anomalies (ileal hamartomatous polyps, colonic hamartomatous polyps,
intussusceptions, rectal bleeding), neurological anomalies (hypotonia, seizures,
thick corpus callosum, intracranial hemangioma), orthopedic anomalies (scoliosis,
joint hyperextensibility, macrodactyly), and dermatological lesions (tan macules on
the glans and the shaft of the penis, acanthosis nigricans, angiokeratoma,
café-au-lait spots, lipomas, hemangiomas, cutis marmorata). The lipomas spontaneously
regress with age. Motor and speech development are delayed, mild mental retardation, and
incoordination are lifelong features. A myopathy caused by abnormal lipid storage can
occur with proved muscle carnitine deficiency. Patients may have an increased risk of
intracranial tumors. An increased incidence of Hashimoto thyroiditis has been suggested.