Congenital limb malformation involving the central
rays of the hands or feet. Ectrodactyly (derived from Greek ektroma [abortion] and
daktylos [finger]) refers to a situation where at least one entire digit (both
metacarpal/metatarsal and phalanges) is missing. It is a nonspecific term
applied to a variety of malformations.
1:90,000 live births (typical split hand); 1:150,000
live births (atypical split hand).
Atypical forms are usually sporadic. Typical
cases (absence of central rays or deficiency of radial rays with no cleft)
are usually inherited as an autosomal dominant trait with complete
penetrance and variable expression. Autosomal recessive forms have been
reported. Five loci for split-hand/foot malformation have been mapped (7q21,
Xq26, 10q24, 3q27, and 2q31).
malformation with absence of multiple fingers varies from monodactyly to
syndactyly. Multiple metacarpal anomalies, radioulnar synostosis, and
tarsal/toe hypoplasia are associated. Other syndromes may coexist with
ectrodactyly, such as the Ectrodactyly, Ectodermal Dysplasia, and
Clefting (EEC) Syndrome.
If ectrodactyly is associated with
EEC syndrome, renal function should be assessed (serum concentrations of
electrolytes, creatinine, urea). Check for signs of central diabetes
insipidus and, if present, evaluate the response to vasopressin treatment.
Optimize intravenous hydration prior to surgery.
Placement of intravenous and arterial
lines and pulse oximeter on the extremities may be challenging. Pay
particular attention to positioning and padding. Because of the hand
deformities, triggering the button of a patient-controlled analgesia (PCA)
device by the patient could be difficult. However, this is not a big problem
for most patients because they encounter similar difficulties on a regular
No special considerations for
isolated ectrodactyly are required.
Because ectrodactyly is a
descriptive term, it may be part of several syndromes.
Anonychia-Ectrodactyly: Absent fingers or oligodactyly, absent
nails and phalanges, osseous and cutaneous syndactyly of fingers.
Ectrodactyly, Ectodermal Dysplasia, and Clefting (EEC) Syndrome: Autosomal
dominant inherited syndrome with maxillary hypoplasia, mild malar
hypoplasia, cleft lip/palate, choanal atresia, hearing loss, photophobia and
blepharophimosis, dacryocystitis, cryptorchidism, hypogonadotropic
hypogonadism renal agenesis or dysplasia, hydronephrosis, occasionally
mental retardation, central diabetes insipidus.
Rüdiger Syndrome: Extremely rare disorder with prominent
forehead, flat nasal bridge, stubby nose, and protuberant upper lip.
Low-pitched and hoarse voice, short digits, and palmar flexion contractures.
Patients may present for inguinal hernia repair.
Saal Bulas Syndrome: Extremely rare syndrome characterized by
diaphragmatic hernia, agenesis of the corpus callosum, and ectrodactyly.
Other features include ventricular septal defect and frequent respiratory
Van den Ende Brunner Syndrome: Extremely rare disorder presenting
with microcephaly, microphthalmia, ectrodactyly of the lower limbs,
premature aging of the skin, and prognathism. Other findings may include
cardiomyopathy, ventricular septal defect, and dysmorphism.
Cleft Hand and Absent Tibia Syndrome: Syndrome characterized by
cleft hand and tibial aplasia with ectrodactyly.