Ulnar Ray Deficiency Research Articles

Ulnar Ray Deficiency: A New Classification and a Unique Case Report

Summary: Ulnar ray deficiency is a rare congenital upper limb defect. We report on a unique case with hand-on-flank deformity on the one side and limb truncation on the contralateral side. The standard of care for the hand-on-flank deformity is to do humerus osteotomy to reposition the hand anteriorly. However, the right limb truncation in our patient made the senior author decide not to do the osteotomy. Final assessment showed that the posterior hand position enabled the patient to reach the ano-genital areas, the pocket, and the mouth. It was concluded that in case of hand-on-flank deformity in one limb and limb truncation of the contralateral limb, osteotomies to bring the hand anteriorly are not advised.

A child with type I ulnar ray deficiency.

A child with type I ulnar ray deficiency.

A Report of Two cases of Al-Awadi Raas-Rothschild Syndrome (AARRS) supporting that “Apparent” Phocomelia differentiates AARRS from Schinzel Phocomelia Syndrome (SPS)

Although there is a long list of syndromes with phocomelia, there are only two syndromes in which there is concurrent pelvic dysplasia and phocomelia: Al-Awadi–Raas-Rothschild syndrome (AARRS) and Schinzel phocomelia syndrome (SPS). Currently, there is a diagnostic confusion between the two syndromes and both have the same MIM entry (MIM 276820). We believe that the two syndromes are different entities and we also believe that the limb defect in SPS is a “true” phocomelia while the limb defect in AARRS is an “apparent” phocomelia. “Apparent” phocomelia describes the most severe form of ulnar ray deficiency in which there is absent ulna with radio-humeral synostosis. “Apparent” phocomelia is diagnosed radiologically by three radiological features: the apparently single bone occupying the arm/forearm appears relatively long, the area of radio-humeral synostosis will have thicker cortex with or without slight angulation, and the lower end of the bone resembles the lower end of a radius and not a humerus. In this paper, we present two new cases of AARRS from two different Saudi Arabian tribes: one case with R292C mutation of WNT7A with bilateral “apparent” phocomelia and a second case with a novel c.814G>T mutation of the WNT7A gene (resulting in wnt7a protein truncation at position 272) with unilateral “apparent” phocomelia. We reviewed previously reported cases of AARRS and SPS to further delineate the differences between these two syndromes. We make the argument that these two syndromes are two different entities and hence require two different MIM entries.

Congenital Upper Limb Deficiencies and Associated Malformations in Finland: A Population-Based Study

To calculate the national incidence of upper limb deficiencies and associated infant mortality in children in Finland using the International Federation of Societies for Surgery of the Hand (IFSSH) classification. Radial ray deficiency, ulnar ray deficiency, central ray deficiency, transverse arrest, phocomelia, undergrowth, and constriction band syndrome with skeletal defects were evaluated. We reviewed upper limb deficiencies among all 753,342 births in Finland during 1993 to 2005 reported to the Finnish Register of Congenital Malformations. Classification of these upper limb deficiencies was done according to a modified IFSSH system. We calculated incidence, gender and side distributions, frequency of associated anomalies, and infant mortality rates in different subtypes of the deficiencies. Familial occurrence of congenital upper limb defects was recorded. A total of 419 cases (234 male, 185 female) of upper limb deficiencies were identified. The national incidence of upper limb deficiencies was 5.56 per 10,000 births and 5.25 per 10,000 live births. The most common upper limb abnormality was radial ray deficiency (138), followed by subgroups of undergrowth (91), upper limb defects due to constriction band syndrome (51), central ray deficiency (41), and ulnar ray deficiency (33). Perinatal mortality was 14%. Infant mortality among children with upper limb deficiencies was 137 per 1,000 live births, compared with an overall infant mortality of 3.7 per 1,000 live births in Finland. Additional birth defects were found in 60% of these children. Prevalence of upper limb defects in relatives of the census population was 2% (11 of 419). The national incidence of upper limb deficiencies is 5.25 per 10,000 live births. Congenital upper limb deficiencies are associated with additional birth defects in two thirds of cases. These children, especially children with radial ray deficiency, have a high perinatal mortality rate. When divided into subgroups using IFSSH classification, differences emerge in both associated anomalies and mortality.

Ulnar Ray Deficiency: a Review of the Classification Systems, the Clinical Features in 72 Cases, and Related Developmental Biology

Ulnar ray deficiency is rare and has a variable presentation. As a result, there are many different classification systems for this anomaly. Furthermore, the developmental biology of the anomaly is still not fully understood. The aim of this article is to review the previous classification systems, present the clinical features in 72 cases and discuss the developmental biology of ulnar ray deficiency.

WNT pathways and upper limb anomalies

The various Wnt pathways that are related to upper limb anomalies are reviewed. Abnormalities in the Wnt7a pathway (located in the dorsal ectoderm) produce several clinically relevant conditions such as the palmar duplication syndrome, nail patella syndrome, ulnar ray deficiency, limb hypoplasia, polysyndactyly and the palmar nail syndrome. Abnormalities of the Wnt3/3a pathway (located in the apical ectodermal ridge) include tetra-amelia and loss of the distal phalanges/nails. Abnormalities of the Wnt5/5a pathway (located in the apical ectodermal ridge as well as in the mesoderm) will affect chondrogenesis of the developing limb and experimental Wnt5a(-/-) limbs have terminal adactyly. Chondrogenesis and limb muscle differentiation are both affected by several Wnt pathways and these will be reviewed in details. Abnormalities in LRP 5/6 (a co-receptor for Wnts) lead to congenital bone disease and Wnt4 is specifically involved in joint development. Finally, the relationship between the Wnt pathway and SALL4 (mutations of which cause Okihiro/Duane-radial ray deficiency in humans) are discussed.

Congenital Duplication of the Palm Syndrome: Gene Analysis and the Molecular Basis of its Clinical Features

Congenital duplication of the palm is a rare syndrome with the following features: the dorsal aspects of both hands have thick palmar skin with no hair or nails; bilateral ulnar ray deficiency; short hypoplastic upper limbs; and severe lower limb abnormalities. In this paper, we report a new case of congenital duplication of the palm syndrome, provide its gene analysis identifying the responsible gene mutation in exon 4 of the WNT7a gene, and detail the molecular basis of its clinical features.

Ulnar ray deficiency A report of a family

We report three cases of ulnar ray deficiency in one family. The father had a left ring finger deficit, and a hypoplastic little finger was amputated at childhood. His first baby had a deep cleft between the ring and little finger in the right hand, and his second baby had complete absence of the left ulna, only one metacarpal, and two digits were present on the hand. All three cases were unilaterally involved and they had no other skeletal abnormalities.

Clinical features and treatment of congenital fusion of the small and ring finger metacarpals

Nine cases of congenital fusion of the small and ring finger metacarpals are reported. The underlying etiology of congenital fusion of the small and ring finger metacarpals was ulnar ray deficiency in four hands, cleft hand in two hands, and symbrachydactyly in one hand; two hands were unclassifiable. X-ray films revealed that the small finger was hypoplastic and accompanied by brachymesophalangy in all cases. It was supposed that the main cause of congenital metacarpal fusion was the deficit of mesenchymal cells. Treatment for metacarpal fusion included splitting the metacarpal fusion and autogenous iliac bone graft in two hands, deepening of the interdigital space in two hands, and amputation of the small finger in one hand. Satisfactory improvement in appearance was achieved in three hands.

Heterotopic Finger Transfer in Ulnar Ray Deficiency Associated with Contralateral Postaxial Polydactyly: A Case Report

A case of type-I ulnar ray deficiency, combined with postaxial polydactyly of the opposite hand, is described. Heterotopic transfer of the supernumerary finger was performed, in order to improve function in the defective hand and to treat the hexadactyly of the other hand. A combination of these malformations has apparently not previously been reported in the literature.

Experimental study of radial ray deficiency

The teratogenic mechanisms of radial ray deficiency were investigated. Radial ray deficiencies were induced in WKAH/Hkm rat foetuses by maternal administration of myleran on day 10, 10.5, or 11 of pregnancy. The skeletal anomalies in rats were similar to those in human beings, suggesting that exposure to some environmental factors at a sensitive period of embryogenesis may cause radial ray deficiency in humans. Ulnar ray deficiency has also been induced in rat foetuses by maternal administration of myleran, so it is suggested that radial deficiency and ulnar deficiency are caused by a common teratogenic mechanism in humans. However, the critical period for radial deficiency is one day later than that for ulnar deficiency in rats, which may contribute to the greater frequency of radial deficiency than ulnar deficiency in clinical cases.

TERATOGENIC MECHANISM OF DRUG-INDUCED ANOMALIES OF EXTREMITIES IN RATS

In order to clarify the teratogenic mechanism of oligodactyly, we have carried out some experimental studies in rats. In this paper we report the results and discuss the teratogenic mechanism of the anomalies of the extremities. 1. Ulnar ray deficiency, cleft hand, central ray polydactyly, and central ray syndactyly were induced in W: Gun rats, and radial ray deficiency was induced only in W KAH/H km rats. The features of these anomalies in rats were the same as in humans. The critical periods of ulnar ray deficiency and radial ray deficiency seemed to be earlier than those of central polydactyly, syndactyly, and cleft hand. The critical period of cleft hand was identical to those of central polydactyly and central syndactyly, and advanced cases of central polydactyly or syndactyly in which the fusion area extended as far as the proximal phalanx and metacarpus, became identical to the cleft hand. These findings suggest that radial and ulnar ray deficiencies belong to longitudinal ray deficiency, and the central polydactyly, syndactyly, and cleft hand might be formed by the same teratogenic mechanism, that is, failure of separation of finger ray. 2. DNA synthesis and cell condensation in the developing hand plate of normal and preaxial oligodactylic rats treated with myleran on the day of 12.0th gestation were examined using a BrdU/anti-BrdU immunohistochemical study. DAN-synthesizing cells were distributed uniformly in the mesenchyme of the hand on day 12.0 in normal rat embryos. From day 13.0. these cells were distributed in the interdigital mesenchymal areas, leaving rare labeled cells in the sites of cell condensation. When the labeled mesenchymal cells were followed from day 12.0 until day 14.0, they were found to be concentrated in the digital rays. We concluded that cell migration rather than cell proliferation in the digital-ray area could be an initial step in digital-ray formation. In the oligodactylic hand plate, mesenchymal cell condensation was delayed and preaxial digital rays were not formed. On day 13.0 the number of DNA-synthesizing cells was much less than normal in all areas of the hand plate, and cell necrosis of the epidermis and mesenchyme near the epidermis was prominent. On day 14.0, DNA-synthesizing cells decreased in the epidermis rather than in the mesenchyme. From these results, we conclude that the mechanism of this oligodactyly could involve a mesenchymal cell deficit and restriction of migration.

Ulnar ray deficiency: Its various manifestations

Eighty-eight upper extremities of 65 patients with ulnar ray deficiency were reviewed with regard to clinical manifestations. Based on the findings, a subclassification into four types was established: type I, hypoplasia or partial defect of the ulna; type II, total defect of the ulna; type III, total or partial defect of the ulna with humeroradial synostosis; and type IV, ulnar defect with congenital amputation at the wrist. Various manifestations of deficiency were evident not only within the ulnar ray but also in other rays. Hypoplasia of the shoulder and/or proximal part of the humerus was present in some cases of types III and IV. Elbow involvement varied from functioning (type I) to acute flexion contracture (type II) to fusion (type III). In 57 hands the digits and carpal bones in the radial ray showed hypoplasia and/or defect. Central digits and carpal bones were also influenced by ulnar ray deficiency, presenting carpal bone fusion, syndactyly, and delta phalanx.

Anomalous hands with cleft formation between the fourth and fifth digits

Three similar cases of cleft hand deformities between the fourth and fifth digits accompanied by hypoplasia of the small finger are reported. After analyses of clinical photographs, radiographs, angiograms, and dermatoglyphic prints of these abnormal hands, it is difficult to fit them into either the ulnar ray deficiency or cleft hand categories of the system of classification adopted by the International Federation of Societies for Surgery of the Hand.

A clinical study of congenital anomalies of the hand

The author has studied the clinical features of split hand, syndactyly, radial and ulnar ray deficiency, and brachydactyly. Many clinical findings make clear that typical split and is not a result of failure of formation but a result of union of digital rays. If we would try to classify congenital anomalies of the hand on the basis of embryological failure, syndactyly and split hand, and webbed and web free brachydactyly are never classified into other categories, just as constriction band syndrome is not divided by the presence of union of the digital rays.

Congenital deficiency of the ulna

Twenty-three patients with ulnar ray deficiency were studied and the deformities described by combining Kummel's and Swanson's classifications. An individualized, functionally oriented management program is recommended with early resection of the fibrocartilaginous remnant to prevent shortening, radial bowing, and possible malrotation. Rotational deformity can be corrected by wedge osteotomy, rotation osteotomy, or proximal radial ulnar synostosis. Improved motion at the elbow can be obtained by release of contractures or resection of the radial head. Wrist deformity may require resection of the ulnar remnant and a wedge osteotomy of the radius.