Ulnar aplasia, dysplastic radius and preaxial oligodactyly: Rare longitudinal limb defect in a sporadic male child
The subject, a 12-year-old school-going boy, originates from a rural area of Southern Punjab, Pakistan. His parents were first cousins (inbreeding coefficient, F = 0.0625), and he had four normal siblings (3 brothers, 1 sister). The maternal and paternal ages were 28 and 33 years, respectively, at the time of his birth. The pregnancy had been uneventful and the birth was at home, in the presence of a traditional birth attendant. The study was approved by the institutional review committee and all the information was obtained according to the Helsinki II declaration. The initial ascertainment and detailed clinical examinations were carried out in several visits during 2009-2010.\nThe subject had normal developmental landmarks, dentition, and intelligence quotient (IQ). He was observed to have an isolated limb anomaly. Upon physical examination, he had a standing height of 146 cm, sitting height 71 cm, arm span 130 cm, head circumference 53 cm, neck circumference 29 cm, and chest 68 cm. There was no family history of any limb or other anomaly.\nClinical examination showed a short left arm []. The upper arm was thin and weak, and the middle and forearm were reduced in size. The elbow demonstrated limited flexion and extension [Figure ,]. The middle arm was flat and depicted restricted supination. The palm was narrow with a few flexion creases []. The ‘hand’ harbored only three functional fingers identified as third, fourth, and fifth, each comprising two flexion creases at the interphalangeal joints. The thumb and index finger were completely omitted. The posterior finger, that is, the fifth digit, was weak and showed volar inclination [Figure ,].\nIn the roentgenograms, the ulna was grossly degenerate and was only represented by a club-shaped decalcified bony island of ~2.5 cm at the distal zeugopod [Figure , ; ]. The radius appeared short, hypoplastic, and dysplastic. In the absence of the ulna, the radius demonstrated a compensatory curvature and maintained a varus concavity of ~20° []. Its proximal head was ill grown, misaligned, and posteriorly dislocated, and was losing its normal axis along the humeral trochanter. The distal head of the radius was broad, weak, and decalcified, depicting signs of immaturity, and was capped with dysplastic epiphysis []. In the upper arm, the humerus was short, thin, and decalcified [; ]. Its distal head was dysplastic with ill-developed epiphysis and hence, was unable to support the zeugopod.\nIn the autopod, four carpals were visible which were crowded and malformed []. Three metacarpals were present which though thin, maintained normal size []. At the anterior axis, the ‘third’ finger depicted volar inclination, whereas at the posterior axis, the ‘fifth’ digit showed clinodactyly []. There was minor cutaneous syndactyly between the fourth and fifth fingers which was not witnessed at the osseous level [] (see for detailed roentgenographic measurements).\nIn the right arm, roentgenograms were unremarkable except for crowding of the carpals. There was no involvement of any other organ system; there were no symptoms of oral, faciocranial, skeletal, or vital internal organs. His parents could not recall any drug exposure during the pregnancy. The subject has fully adapted this limb deficiency and can manage his daily life activities well.