Genetic disorder characterized by a characteristic
facies, marfanoid habitus, and mental delay.
Arachnodactyly\ Mental\ Retardation\ Dysmorphism Syndrome.
Approximately 10 cases have been described.
Postulated to be autosomal recessive.
Symptoms of the syndrome are apparent at birth.
Diagnosis is based on physical signs of arachnodactyly and the
characteristic facies associated with mental retardation.
Facies is long, narrow, and triangular in shape,
with a large forehead and brachycephalic skull. Other facial characteristics
are hypertelorism, microstomia with thin lips and flat philtrum, and an
underdeveloped maxilla. Moderate-to-severe mental retardation with or
without seizures is found. Patients present with long slender extremities,
arachnodactyly comparable to Marfan syndrome, and, in some cases,
hyperextensible joints. Finger and toe anomalies, such as clinodactyly of
the fourth and fifth fingers, triphalangeal thumbs, and hammer-shaped toes,
can be present. Patients may be hypotonic with increased reflexes and
underdeveloped musculature. Development of the external genitalia is
delayed. Mitral regurgitation has been described in one case.
Evaluate the airway carefully. If a
cardiac lesion is suspected, obtain an ECG and an echocardiogram.
Direct laryngoscopy and tracheal intubation
may be challenging. An inhalation induction while the child is kept spontaneously
breathing probably is the best choice, considering the child is mentally delayed and
can hardly cooperate with an awake fiberoptic intubation. In the presence of
a cardiac lesion, antibiotic prophylaxis for subacute bacterial endocarditis
should be given.
Secondary to the generalized
hypotonia and poorly developed musculature, neuromuscular blocking agents
may not be needed at all or only in a reduced dosage. If the patient is on
anticonvulsant medication, liver enzymes may be induced and hasten the
metabolism of drugs with predominantly hepatic metabolism.
Lujan Fryns Syndrome: Inherited syndrome with marfanoid features
and X-linked mental retardation.
Marfan Syndrome: Autosomal dominant inherited disorder with
generalized connective tissue abnormalities. Aortic regurgitation and
dissection are responsible for premature death in the third to fifth decade.
de Die-Smulders C, Vles H, Fryns JP: Characteristic facial dysmorphism,
arachnodactyly and mental handicap in two unrelated girls: A distinct MCA/MR
syndrome? Genet Couns 4:165, 1993.
Mégarbané A, Chammas C: Severe mental retardation with marfanoid
habitus in a young Lebanese male. A diagnostic challenge. Genet Couns
Van Buggenhout GJCM, Akkermans-Scholten ACM, Hamel BCJ: Characteristic
facial dysmorphism, arachnodactyly and mental retardation: Another case.
Genet Counsel 6:61, 1995.