Content area
A 94-year-old woman admitted with confusion secondary to a urinary tract infection exhibited deformities in all four limbs that were present from birth. Her appearance was suggestive of split hand/split foot malformation a rare congenital condition that affects the central rays of the distal limb portion. She had no syndromic features and had lived without support or assistance of her daily activities. A keen knitter, she regularly knitted for her three grandchildren, all of which, along with her son, were unaffected by this condition.
Full text
Correspondence to Dr Muhammad Javaid Hameed Rahmani, [email protected]
Background
Split hand/split foot malformation (SHFM) is a rare congenital condition that results in variable levels of developmental hypoplasia or aplasia of the distal hands and/or feet.
Case presentation
A 94-year-old woman admitted with confusion due to a urinary tract infection was seen to have significant malformation of her hands and feet. Her presentation was consistent with SHFM) or ectrodactyly. Her defects were largely symmetrical with each limb showing slight variations that were confirmed radiologically. Her hands are shown in (figures 1 and 2) and her feet are shown in (figure 3). She was otherwise physically well with no syndromic features. There were no reports of SHFM in her siblings, parents, son or three grandchildren.
Figure 2. Posterior aspects of the hands—on the right hand, there is an absence of the thumb and major deformities in the distal two fingers and there is syndactyly of the remaining second and third digits on the right hand. On the left hand, there is a visible absence of the thumb, fourth and fifth digits. The index and middle fingers look largely intact. There is an area of swelling around the proximal interphalangeal joint of the third digit.
Figure 3. Image of both feet—feet showing symmetrical absence of multiple toes with only the first, fourth and fifth remaining. There is syndactyly of the lateral two toes. Both feet showed a large cleft in the central region of the foot giving the characteristic ‘lobster claw’ appearance.
Investigations
Radiographs of both hands and feet were performed to assess the skeletal structure (figures 4 and 5).
Figure 4. Left and right hands—(A) There is an absence of the thumb with hyperplasia of the second and third metacarpals with hyperplasia of the third proximal phalanx and absence of middle and distal phalanges. There is hypoplasia of the fourth and fifth metacarpals with associated deformities of the phalanges. (B) There is agenesis of the thumb with hyperplasia of the second metacarpal and absent phalanges. The third, fourth and fifth metacarpals are hypertrophic. There is absence of the middle and distal phalanges of the middle finger. There are deformities of the fourth and fifth phalanges.
Figure 5. Left and right feet—there is a classical ‘lobster claw’ deformity of the right and left feet with absence of the second and third metatarsal rays bilaterally. There is a severe hallux valgus deformity on the right.
Treatment
Reconstructive surgery is an option for applicable candidates with SHFM. Prosthetics may also be available to improve activities of daily living and aesthetic appearance. The degree of disability will depend on the severity of the phenotype, but in this case her deformity had not affected her ability to live independently. Where relevant, genetic counselling is of benefit for patients planning to have children. Our patient had reported that no genetic testing or investigations had ever been carried regarding this condition.
Outcome and follow-up
She had carried out a normal life despite being significantly affected with deformed hands and feet, raised a child without any support and had a regular hobby of knitting.
Discussion
SHFM is a rare congenital condition that features a range of presentations with varying degrees of digital hypoplasia and clefting of the hands/feet that gives a characteristic ‘lobster claw’ appearance.1
Prevalence is 1 in 18 000 births and has no gender preference. SHFM can be inherited through an autosomal dominant or recessive trait, X-linked recessive trait or be the result of a sporadic mutation,2 the latter being the most common.3 It can also present as part of a syndrome or as an isolated finding.
Seven different chromosomal loci and point mutations in three signalling pathway genes have been identified, these being TP63, WNT10B and DLX5.4 Three cases of SHFM involving consanguineous families were due to mutations in the WNT10B gene.5 Mutations in the TP63 gene, which is homologous to the tumour suppressor gene TP53, are present in over 90% of patients with a syndromic phenotype of SHFM known as ectrodactyly–ectodermal dysplasia–cleft lip/palate syndrome.6 Where four limbs are affected and there is a non-syndromic presentation the aetiology is likely due to an autosomal dominant genetic mutation with reduced penetrance, a factor that was not present in our case making it likely to have been of sporadic origin.
Learning points
Split hand/split feet malformation or ectrodactyly is a rare condition.
Patients wanting to have children may be genetically screened and appropriately counselled due to autosomal and X-linked inheritance.
Management options include surgery, prosthetics or supportive measures to improve appearance and functioning of the affected limbs.
Patients have normal life expectancy with minimal or no support despite significant deformity.
Contributors AA was involved in obtaining the case history literature search and patient images. LD was involved in the case report and identifying references for learning points. MJHR in formulating the idea for the case report, discussion and amalgamating learning points.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
1 National Organization for Rare Disorders (NORD), 2004. Split Hand /Split Food Malformation https://rarediseases.org/rare-diseases/split-handsplit-foot-malformation/.
2 Jindal G, Parmar VR, Gupta VK. Ectrodactyly/split hand feet malformation. Indian J Hum Genet 2009;15:140–2. DOI::10.4103/0971-6866.60191
3 Duijf PHG, Bokhoven H, Brunner H. Pathogenesis of split-hand/split-foot malformation. Hum Mol Genet 2003;12:51R–60. DOI::10.1093/hmg/ddg090
4 Sowińska-Seidler A, Socha M, Jamsheer A. Split-hand/foot malformation - molecular cause and implications in genetic counseling. J Appl Genet 2014;55:105–15. DOI::10.1007/s13353-013-0178-5
5 Ashi M, Assur R, Awan B, et al. Bilateral split hand foot malformation in siblings: Case series. Int J Surg Case Rep 2018;44:114–7. DOI::10.1016/j.ijscr.2017.12.030
6 Gane BD, Natarajan P. Split-hand/feet malformation: A rare syndrome. J Family Med Prim Care 2016;5:168. DOI::10.4103/2249-4863.184656
Copyright BMJ Publishing Group LTD 2018