Split-hand/feet malformation: A rare syndrome

A human embryonic limb cell atlas resolved in space and time

Human limbs emerge during the fourth post-conception week as mesenchymal buds, which develop into fully formed limbs over the subsequent months1. This process is orchestrated by numerous temporally and spatially restricted gene expression programmes, making congenital alterations in phenotype common2. Decades of work with model organisms have defined the fundamental mechanisms underlying vertebrate limb development, but an in-depth characterization of this process in humans has yet to be performed. Here we detail human embryonic limb development across space and time using single-cell and spatial transcriptomics. We demonstrate extensive diversification of cells from a few multipotent progenitors to myriad differentiated cell states, including several novel cell populations. We uncover two waves of human muscle development, each characterized by different cell states regulated by separate gene expression programmes, and identify musculin (MSC) as a key transcriptional repressor maintaining muscle stem cell identity. Through assembly of multiple anatomically continuous spatial transcriptomic samples using VisiumStitcher, we map cells across a sagittal section of a whole fetal hindlimb. We reveal a clear anatomical segregation between genes linked to brachydactyly and polysyndactyly, and uncover transcriptionally and spatially distinct populations of the mesenchyme in the autopod. Finally, we perform single-cell RNA sequencing on mouse embryonic limbs to facilitate cross-species developmental comparison, finding substantial homology between the two species.

Three-dimensional CT angiography for surgical planning in congenital hand malformations: a case series presentation

Between January 2000 and December 2019, three-dimensional computer tomographic (CT) angiography was used in a total of 140 hands (116 patients, mean age 6.8 years) with congenital hand malformation to assess the vascular and bony structures. Analysis showed overall satisfactory three-dimensional CT images for operative planning, including detailed abnormal vascular patterns and bony malformations. Among the 116 patients, six patients with typical findings of a few malformations are reported in detail. Pitfalls in interpretation of the images and the use of three-dimensional CT angiography in surgical planning are discussed. We conclude that three-dimensional CT angiography is useful for preoperative planning of complex congenital hand malformations.Level of evidence: IV.

Cleft foot: A case report and review of literature

BACKGROUND

Cleft foot is a very rare congenital anomaly, which is characterized by central rays deficiency of the foot. It is also known as split foot or ectrodactyly of the foot, and it is very often combined with splitting of the hands. The defect develops due to insufficient activity of the median apical ectodermal ridge, which leads to an increase in cell death or a decrease in cell proliferation. Due to the rarity of the pathology, there are few papers on the surgical treatment of this congenital foot disease, and publications to date concern the treatment of children.

CASE SUMMARY

We present a clinical case of congenital splitting of the feet and hands in a 31-year-old woman and a long-term result of foot treatment using the minimal arrangement of the Ilizarov apparatus. The patient had paternal inheritance of the trait. After the surgical treatment, cosmetic view and functional condition of the foot were improved and persisted two years after intervention. There were no complications in the treatment process.

CONCLUSION

The possibility of dosed control and stable fixation of the foot rays made it possible to create favorable conditions for the healing of the central wound and the closure of the segment splitting without complications. The long-term outcome of the treatment of foot congenital splitting using the proposed Ilizarov apparatus arrangement has shown its effectiveness. Our approach should be considered as an option of treatment in similar cases.

A Novel Homozygous Nonsense Mutation p.Cys366* in the WNT10B Gene Underlying Split-Hand/Split Foot Malformation in a Consanguineous Pakistani Family

Split hand/split foot malformation (SHFM) or ectrodactyly is characterized by a deep median cleft of the hand or foot, hypoplasia or aplasia of the metacarpals, metatarsals, and phalanges. It is a clinically and genetically heterogeneous group of limb malformations. This study aimed to identify the pathogenic variant in a consanguineous Pakistani family with autosomal recessive SHFM. Peripheral blood samples were obtained, DNA was extracted, WNT10B coding and noncoding regions were PCR amplified and Sanger sequencing was performed using workflow suggested by Thermo Fisher Scientific. A novel homozygous nonsense variant (c.1098C>A; p.Cys366*) was identified in the WNT10B gene in the index patients, which probably explains SHFM type 6 in this family in comparison with similar data from the literature.

Lady with ‘lobster claw’ feet

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.