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Inherited disorder characterized by excessive growth
prenatally and postnatally manifesting with macrocephaly and scaphocephaly
with normal intelligence or mild mental retardation and multiple hamartomas
(lipomas, intestinal polyps). As affected infants age, the growth rate slows
down and commonly results in normal adult height.
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Bannayan-Riley-Ruvalcaba Syndrome; Ruvalcaba-Myhre-Smith
Syndrome.
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Unknown, but several case reports exist.
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Presumed autosomal dominant inheritance with
male predominance (up to 80% of cases). Variability in the severity of
the condition in affected individuals suggests allelic mutations or possible
genetic heterogeneity. The gene for Bannayan-Zonana syndrome has been
localized to the q22-23 region within the PTEN (phosphate and tensin)
homologue locus of chromosome 10. The Bannayan-Zonana syndrome should be
unified into a single entity with other similar, previously considered
separate syndromes, namely, Riley-Smith, Ruvalcaba, Cowden, and
Lhermitte-Duclos. Clinical and molecular data support the unification with
the proposed new nomenclature PTEN-MATCHS syndrome.
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Multiple hamartomas with various angiomatous,
lymphangiomatous, and lipomatous constituents. Muscle biopsy demonstrates a
lipid storage myopathy with increased depositions of lipid droplets in type
I fibers. Type II fibers are smaller than normal. Lipid myopathy may result
from a defect in long-chain fatty acid oxidation, which is caused by a
deficiency of long-chain L-3-hydroxyacyl-CoA dehydrogenase.
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Clinical features and muscle biopsy. Electromyography is
consistent with a myopathic condition.
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Increased birth weight (>4 kg [8.8 lb]) and
length (>97th percentile), with normal adult height are typical.
Macrocephaly, macroencephaly, scaphocephaly, and delayed closure of
fontanelles. Intracranial manifestations include increased incidence of
intracranial tumors, hemangiomas, arteriovenous malformations, hemorrhage,
and seizure activity. Extracranial arteriovenous malformations occur.
Delayed psychomotor development with dyscoordination, myopathy, and
hypotonia. Intelligence may be normal or mildly retarded. Increased
salivation and drooling. Ophthalmologic features consist of strabismus
(exotropia), hypertelorism, and pseudopapilledema. High-arched palate.
Hashimoto thyroiditis has been reported in affected individuals. Pectus
excavatum. Juvenile intestinal polyposis with increased risk of
intussusception. Protein-losing enteropathy and hepatomegaly may occur.
Intestinal and skin lipomas tend to regress with age. Thumbs and great toes
are broad (clubbing). Skin manifestations include hemangiomas, multiple
lipomas, telangiectases, café-au-lait spots, facial acanthosis
nigricans-like discoloration, and cutis marmorata. Penis may be enlarged
with spotted pigmentation of the glans. Thyroid and breast tumors may be
malignant.
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Detailed clinical history and
examination to evaluate the extent of systemic involvement: neurologic
status, intracranial pathology (tumor, hemangiomata), signs of increased
intracranial pressure, seizures (anticonvulsant therapy), and mental
retardation (sedative premedication may be valuable in the absence of increased intracranial pressure); cardiovascular status
(heart failure secondary to arteriovenous malformation, heart failure
medication); and respiratory status (myopathy, hypotonia, degree of pectus
excavatum, potential respiratory compromise). Evaluate the airway for
potential difficulties (high-arched palate, macrocephaly). Anticholinergic
premedication may be beneficial if salivation is excessive. Obtain blood
work with complete blood count, electrolytes, urea, liver function tests,
and thyroid function tests.
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If difficult airway management is
anticipated, an awake fiberoptic tracheal intubation (mental retardation may
reduce cooperation) or inhalational ...