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An inherited syndrome with mental deficiency
and endocrine disorder.
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First described in 1962 by M. Börjeson, H. Forssman,
and J. O. Lehmann.
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Transmitted as an X-linked recessive trait,
thus, predominantly males are affected, although heterozygous female
carriers may manifest certain, although much more variable, features of the
disease (suggesting X-linked incomplete recessive inheritance). Gene map
locus is Xq26-q27. The mutations seem to affect the PHF6 gene
(plant homeodomain zinc-finger transcription factor gene), which is involved in
DNA-transcription.
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Based on the clinical appearance. Characteristic facial
appearance (round, fatty face with large, protruding tongue, large but
normally formed ears, relative microcephaly, prominent brow ridge, deep-set
eyes, ptosis) associated with mental retardation and epileptic attacks. No
known biochemical or cytogenetic markers.
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Mild-to-severe intellectual handicap, epilepsy,
hypogonadism (hypogonadotropic hypogonadism with delayed second-degree
sexual characteristics), hypometabolism, marked obesity, swelling of
subcutaneous facial tissue, short neck, short stature and narrow palpebral
fissure. Hyperkyphosis that increases with age was reported.
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The patient's history should be
evaluated in relation to seizures, current anticonvulsant therapy, and
complications resulting from the therapy in particular. Plasma
anticonvulsant levels may require determination and the dose optimized to
ensure adequate levels. Marked obesity necessitates systematic review of
associated cardiovascular and respiratory diseases. The airway should be
assessed because difficulty in direct laryngoscopy is not uncommon in these
patients. Cardiac function should be evaluated carefully, as one case of a
19-year-old patient who presented for heart transplantation secondary to
dilated cardiomyopathy was reported. Cardiac function should be assessed in
the presence of morbid obesity (to exclude pulmonary hypertension) and
hypometabolism with electrocardiogram, chest radiography, echocardiography, and, if
necessary, radionuclide imaging. Carefully evaluate respiratory function in
the presence of hyperkyphosis (including lung function tests).
H2-antagonist therapy may be indicated to reduce the risk of pulmonary
aspiration. Premedication with respiratory depressant drugs should be
avoided in morbidly obese patients. Recommended laboratory investigations
include complete blood count, electrolytes, arterial blood gas analysis,
urea, and occasionally anticonvulsant plasma levels.
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Difficult cooperation as a result of
mental retardation is possible. Marked obesity makes vascular access
difficult and desaturation on induction more likely than in nonobese
patients. Adequate preoxygenation should be given prior to induction of
anesthesia. In the morbidly obese in whom difficult tracheal intubation is
anticipated, direct laryngoscopy under topical anesthesia may be helpful. If
the larynx is visualized, a rapid sequence induction should be performed to
prevent desaturation and minimize risk of pulmonary aspiration. If the
larynx cannot be visualized, an awake fiberoptic tracheal intubation is the
safest approach. Mechanical ventilation is preferred over spontaneous
breathing as tidal volume breathing falls within the closing volume range
and commonly results in hypoxemia. A regional anesthesia technique, such as
spinal or epidural anesthesia, requires reduced doses of local anesthetics
(75-80% of regular dose). Continuous oxygen therapy, physiotherapy, and
deep venous thrombosis prophylaxis with early mobilization (if possible) are
required in the ...