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Acronym for lentigines (multiple),
electrocardiographic conduction abnormalities, ocular hypertelorism,
pulmonary stenosis, abnormal genitalia, retardation of growth, and deafness
(sensorineural). Complex congenital dysmorphogenetic disorder associating
mainly skin lesions (lentigines), severe cardiac anomalies (dysrhythmias,
pulmonary valve stenosis), ocular hypertelorism, abnormalities of genitalia,
sensorineural deafness, and severe retardation of growth.
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Cardiocutaneous Syndrome; Cardiocutaneous Lentiginosis
Syndrome; Cardiomyopathic Lentiginosis; Centrofacial Lentiginosis;
Generalized Lentiginosis; Lentiginosis-Deafness-Cardiopathy Syndrome;
Lentiginosis Profusa Syndrome; Moynahan Syndrome; Multiple Lentigines
Syndrome; Progressive Cardiomyopathic Lentiginosis.
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First described by Zeisler and Becker in 1936. It has many
similarities to Noonan syndrome, except in the most striking features, from
which its name is derived. The mnemonic was first used by Gorlin et al. in
1969.
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Rare; slightly more than 80 cases reported. Life
expectancy is normal.
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Sporadic or autosomal dominant. Single mutant
gene with high penetrance and variable expression produces the defects in
this syndrome. Slight male predominance.
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Mutation in the stem cell pool of the neural crest
in embryonic life is regarded as a common cause of cutaneous (producing
lentigines), neurologic, cardiac (resulting in cardiomyopathy), and possibly
urogenital defects. Metabolism of dihydroxyphenylalanine (DOPA),
epinephrine, and norepinephrine is altered, which may result in abnormal
skin pigmentation.
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Diagnostic criteria included skin lentigines plus two other
recognized features or a first-degree relative with lentigines plus three
other features in the patient. Histologic examination of the lentigines
shows pigment accumulation in the dermis and in the deeper layers of
epidermis. There is an increase in melanocytic density owing to corrugation
of the dermoepidermal junction.
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Lentigines (1-2 mm; flat, dark brown-to-black
cutaneous lesions) can be present at birth and increase in number until
puberty. They are most numerous on the face, neck, and upper trunk but spare
the mucous membranes. Valvular pulmonary stenosis is the most common (40%
of cases) cardiovascular abnormality. Hypertrophic obstructive
cardiomyopathy is a major concern with onset usually in childhood.
Subsequent progression may be mild and slow or severe and florid with rapid
decompensation. Conduction abnormalities are common and result from
combinations of blocks in the bundle branch system. These abnormalities may
be asymptomatic or sufficiently severe to provoke sudden death. The
conduction impairment develops gradually and is progressive. Ocular
hypertelorism, mandibular prognathism, and short stature are the most common
skeletal abnormalities. Pectus excavatum and carinatum are common, as is
scoliosis (10% of cases). Sensorineural hearing loss may be severe and
may appear late in life.
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Echocardiographic examination to
look for the presence of cardiomyopathy, pulmonary valve stenosis, and subaortic
stenosis (with outflow tract obstruction) is mandatory. Evaluate pulmonary
function (when feasible ...