|Year : 2015 | Volume
| Issue : 1 | Page : 53-55
Ectrodactyly: A rare anomaly of limbs
Nirmala SVSG, Sandeep Chilamakuri, Chaitanya Pavuluri, Sivakumar Nuvvula, Sindhuri Veluru
Department of Paedodontics and Preventive Dentistry, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India
|Date of Web Publication||16-Mar-2015|
Dr. Nirmala SVSG
Professor, Department of Paedodontics and Preventive Dentistry, Narayana Dental College and Hospital, Nellore - 524 003, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
Ectrodactyly refers to the congenital limb malformation, characterized by a deep median cleft of the hand and/or foot due to the absence of central rays. Affected individuals may be recognized by a lobster-claw deformity of their limb extremities that causes severe functional disorders. A combination of ectrodactyly, ectodermal dysplasia and cleft (EEC) in the lip or palate is called as EEC syndrome. This paper reports a case of the nonsyn dromic form of ectrodactyly in a 9-year-old girl along with etiological factors and its management.
Keywords: Nonsyndromic ectrodactyly, split foot malformation, split a hand
|How to cite this article:|
SVSG N, Chilamakuri S, Pavuluri C, Nuvvula S, Veluru S. Ectrodactyly: A rare anomaly of limbs. J NTR Univ Health Sci 2015;4:53-5
| Introduction|| |
Ectrodactyly or split hand/split foot malformation (SHFM), by strict definition is the congenital absence of central rays of limbs.  The term ectrodactyly originates from the Greek words - Ektroma (abortion) and daktylos (finger).  Ectrodactyly was first documented in 1770 among a tribe of Guiana Indians.  von Walter described the crab-claw deformity in 1829, and Cruveilhier first used the term "lobster-claw" in 1842. 
Split hand/split foot malformation is a rare congenital deformity of the hand/foot, in which the middle digits are missing, and hand/foot is cleft at metacarpal/tarsal area. The hand/foot appears like a lobster-claw, thus the nickname "lobster-claw deformity."
In ectrodactyly, the basic embryologic abnormality is failure to maintain normal functioning apical ectodermal ridge, leading to failure to differentiate the autopod (hand or foot).
Ectrodactyly occurs in two forms, either as an isolated disorder or as a component of a syndrome. Any of these two forms can be sporadic or familial, sporadic cases are being more common.  The most frequent pattern of inheritance is autosomal dominant with reduced penetrance. Autosomal recessive  and X-linked forms of transmission,  are less frequent while other cases of ectrodactyly are caused by chromosomal deletion and duplication.  Common anomalies associated with ectrodactyly include the tibial aplasia, craniofacial defects and genitourinary abnormalities. Ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC) is the prototypical example of ectrodactyly syndrome accompanied by multiple organ defects. It is defined by a triad of EEC lip and palate. 
Ectrodactyly is relatively common in few central African communities with possible common progenitor.  According to the literature, ectrodactyly associated with the syndrome is rare and isolated ectrodactyly is even more rare entity.
| Case Report|| |
A 9-year-old girl came for routine dental check-up to the Department of Pedodontics. She was born at full-term after an uncomplicated pregnancy to a 27-year-old mother and a 29-year-old father. She was the first child of unrelated and clinically normal parents. No toxicity, infections, traumatic or X-rays exposure were reported. Furthermore, physical and systemic examination were normal except for the musculoskeletal system, which revealed cleft affecting both hands and feet. The index and middle fingers of her right hand were completely missing [Figure 1]. Six fingers were present on the left hand in which 3 rd and 4 th fingers are diminutive and absence of 2 nd and 3 rd toe in both the lower limbs [Figure 2].
There were no problems with her psychological faculties and her scholastic achievements were commensurate with her chronologic age.
Extra oral and intra oral soft tissue examination were normal. She had mixed dentition with Angle's class I molar relationship; mandibular right first primary molar was grossly decayed. Preventive measures were performed, and mandibular right first primary molar was extracted and a space maintainer was given.
X-ray of the right hand revealed absence of 2 nd , 3 rd phalanges and presence of 1 st , 4 th , 5 th phalanges in which 1 st phalanx was bifid with articulations. In the left hand, 1 st , 2 nd , 4 th and 5 th phalanges are normal, and two phalanges are derived from 3 rd metacarpal, hence giving the appearance of six fingers [Figure 3].
|Figure 3: X-ray of the right hand revealed absence of 2nd and 3rd phalanges and presence of 4th and 5th phalanges, bifid with articulations of 1st phalanx in the right hand|
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X-ray of the foot showed absence of 2 nd , 3 rd phalanges and metatarsals [Figure 4].
She has only younger brother aged about 7 years, and he does not have any problems.
| Discussion|| |
Ectrodactyly is a rare genetic disorder with an incidence of 1:90,000 live births with no sex predilection. , Other syndromes associated with ectrodactyly include Carpenter's syndrome, Delange syndrome, Goltz syndrome and Miller syndrome,  in the presented case patient did not have any associated syndromes. Genetically SHFM has been found to be heterogeneous, with mutations identified at 5 loci (SHFM1 at 7q21.3, SHFM2 at xq26, SHFM3 at 10q24, SHFM4 at 3q27 and SHFM5 at 2q31).
The usual presentation involves hands and feet bilaterally, cases of cleft hands and feet without other manifestations have been described , but are very rare.
Syndromes in which ectrodactyly is associated with other abnormalities can occur when two or more genes are affected by a chromosomal rearrangement. This explains the association of SHFM with other congenital anomalies in patients with deletions in 2q31 or 7q21. In contrast, syndromic ectrodactyly may also be the result of a single gene defects. The most common and best known human SHFM syndrome is EEC syndrome, which is caused by missense mutations in the TP63 gene.  EEC syndrome is characterized by EEC of the lip/palate. In contrary, only ectrodactyly was present our patient.
Barsky has described two types of cleft hand.  One is typical cleft hand with a deep palmar cleft, which separates the two central metacarpals. It is often bilateral and may involve the feet. Our case belongs to this type. Usually, the middle or an index ray is deficient in a V-shaped deformity.
In the atypical cleft hand, the central rays are absent, and only short radial and ulnar digits remain with a shallow cleft giving a U-shaped deformity. The thumb and little finger usually are the best-developed digits on the hand. This deficiency is usually unilateral, and a family history seldom is present. Other associated abnormalities include cleft lip and palate, reduction in number and size of the phalanges, syndactyly, polydactyly, triphalangeal thumb, scalp defect, genitourinary anomalies with atresia of the nasolacrimal duct and buphthalmos.
Blauth and Borisch  presented a radiographic classification of cleft feet into six levels. They also described a polydactylous type with central cleft and polydactyl, and a diastatic type in which there is lower leg diastasis, a partial tibial aplasia, or both. In the present case, the patient belongs to grade IV according to the classification [Table 1].
| Conclusion|| |
Ectrodactyly is uncommon; even rarer are descriptions in the literature of suitable techniques of treatment. Whenever a child presents with limb anomalies, associated orofacial manifestations should be keenly observed. Parents should be counseled for the possibility of recurrence of the disease in the future siblings. A three-dimensional sonographic image of this anomaly confirms the diagnosis. Most cases of isolated ectrodactyly do not require surgical intervention and lives with modest functional impairment of the limbs.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]