Ectrodactyly

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.

Absent Finger Syndrome.

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).

Unknown.

This “split-hand/foot” 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 basis.

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 distress.

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.