Mid-term foot function and pedobarographic analysis of 52 feet after polydactyly resection in childhood.

AIMS: The aims of this study is to report the clinical and radiological outcomes after pre-, central-, and postaxial polydactyly resection in children from a tertiary referral centre. METHODS: All children who underwent resection of a supernumerary toe between 2001 and 2013 were prospectively enrolled and invited for a single re-assessment. Clinical parameters and several dedicated outcome scores (visual analogue scale (VAS), Paediatric Outcomes Data Collection Instrument (PODCI), Activities Scale for Kids (ASK), and American Orthopaedic Foot and Ankle Society Score (AOFAS)) were obtained, as were radiographs of the operated and non-operated feet along with pedobarographs. RESULTS: In all, 39 children (52 feet) with a mean follow-up of 7.2 years (3.1 to 13.0) were included in the study. Resection of a duplicated great toe was performed in ten children, central polydactyly in four, and postaxial polydactyly in 26. The mean postoperative VAS (0.7; 0 to 7), ASK (93.7; 64.2 to 100), and AOFAS range (85.9 to 89.0) indicated excellent outcomes among this cohort and the PODCI global functioning scale (95.7; 75.5 to 100) was satisfactory. No significant differences were found regarding outcomes of pre- versus postaxial patients, nor radiological toe alignment between the operated and non-operated sides. Minor complications were observed in six children (15%). There were seven surgical revisions (18%), six of whom were in preaxial patients. In both groups, below the operation area, a reduced mean and maximum force was observed. Changes in the hindfoot region were detected based on the prolonged contact time and reduced force in the preaxial group. CONCLUSION: Excellent mid-term results can be expected after foot polydactyly resection in childhood. However, parents and those who care for these children need to be counselled regarding the higher risk of subsequent revision surgery in the preaxial patients. Also, within the study period, the plantar pressure distribution below the operated part of the foot did not return to completely normal. Cite this article: Bone Joint J 2021;103-B(2):415-420.

Bardet-Biedl syndrome presenting with laryngeal web and bifid epiglottis.

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathy characterised by rod-cone dystrophy, obesity, postaxial polydactyly, cognitive impairment, hypogonadism, renal abnormalities, and rarely, laryngeal webs or bifid epiglottis. Most patients present with obesity. Multiple genes are involved in causation of BBS and there is also evidence of triallelic inheritance. We herein report an Asian boy who had weak cry and stridor since birth, and on evaluation was found to have both laryngeal web and bifid epiglottis. Mutation analysis revealed a homozygous variant in BBS10 gene.

High prevalence of Bardet-Biedl syndrome in La Réunion Island is due to a founder variant in ARL6/BBS3.

Bardet-Biedl syndrome (BBS) is a rare ciliopathy with variable retinal dystrophy, polydactyly, renal abnormalities, obesity, cognitive impairment, and hypogonadism. Biallelic pathogenic variants have been identified in 24 genes, leading to BBS in an autosomal recessive inheritance pattern. In this study, we investigated a cohort of 16 families (20 individuals) presenting with typical BBS originating from La Réunion Island using sequencing (Sanger and high-throughput methods) and SNP array. In eight families (12 individuals) we identified the same ARL6/BBS3 variation [c.535G > A, p.(Asp179Asn)]. Bioinformatics and functional analyses revealed an effect of this variant on the splicing of ARL6/BBS3. Owing to the relatively high frequency of this variant, a possible founder effect was suspected. Genotyping of six individuals revealed a common 3.8-Mb haplotype and estimated the most recent common ancestor to about eight generations confirmed by the known genealogy. Knowledge of this founder effect modifies our diagnostic strategy and enables a personalized genetic counseling for patients from La Réunion Island. Being the first description of BBS patients from La Réunion Island, we could estimate its prevalence between ~1/45000 and ~ 1/66000 individuals.

TGDS pathogenic variants cause Catel-Manzke syndrome without hyperphalangy.

Catel-Manzke syndrome, also known as micrognathia-digital-syndrome, is a rare autosomal recessive disorder characterized by the combination of the two cardinal features Pierre-Robin sequence and bilateral hyperphalangy leading to ulnar clinodactyly (ulnar curvature of the phalanges) and radial deviation (radial angulation at the metacarpophalangeal joint) of the index fingers. Individuals without one of these major hallmarks or with additional hand malformations have been described as atypical or Catel-Manzke-like syndrome. Biallelic TGDS pathogenic variants have thus far been detected in eight individuals with typical Catel-Manzke syndrome and in one fetus with additional features. Here we report on two individuals with TGDS pathogenic variants who presented with mild radial deviation and ulnar clinodactyly of the index fingers but without radiologic signs of hyperphalangy. Furthermore, both individuals have disproportionate short stature, a feature that has not yet been associated with Catel-Manzke syndrome. Our data broaden the phenotypic spectrum of TGDS-associated Catel-Manzke syndrome and expand the indication for diagnostic testing.

Mosaic trisomy 20 and mitigation in capital crimes sentencing: A review and case report.

Trisomy 20 is a genetic abnormality in which individuals have an extra copy of chromosome 20. Complete trisomy 20 is rare and believed to be incompatible with life. A mosaic form of trisomy 20, in which only some cells or tissues contain the extra chromosome, is a relatively commonly encountered chromosomal abnormality found during prenatal testing, and c. 90% result in a normal phenotype. However, despite the absence of a consistent phenotype, certain findings have been reported across multiple cases of mosaic trisomy 20. These include an array of morphological findings, developmental delays, and learning disabilities. Beyond physical manifestations, a wide range of developmental and learning delays have also been reported. In this work, we provide an overview of the trisomy 20 literature and a case report of a young adult male with mosaic trisomy 20 who committed homicide. His developmental and life history, eventual diagnosis of mosaic trisomy 20, similarities and differences in his condition compared with prior research findings, and potentially new phenotypic findings associated with trisomy 20 that he manifested (childhood visual hallucinations, self-injury, polydactyly) are presented. Additionally, the potential role of this genetic diagnosis in his neuropsychiatric history and its successful application as a mitigating factor at his capital sentencing trial are described. We did not identify other similar cases during our search of major scientific and legal databases. As a backdrop, the use of genetics in criminal trials is on the rise, and courts are increasingly likely to accept behavioral genetics evidence; therefore, it is crucial that the legal system is well acquainted with the opportunities and limitations of these approaches.

Long-Term Results of Surgically Treated Radial Polydactyly - An Outcome Correlation Study.

Background: Thumb polydactyly is one of the commonest congenital hand differences. Traditional surgeon-based outcome scores capture outcomes mainly on bodily structure and function. Outcomes on the long-term well-being of the patients in the domains of activity and participation are not fully studied. Methods: Forty-eight thumbs in forty-five Chinese patients with radial polydactyly underwent surgical treatment at or before 3 years old were recruited. Mean follow-up was 11.6 years. Surgical outcomes were collected and compared to the normal opposite thumb. The results were compiled into the Japanese Society for Surgery of the Hand (JSSH) score, Cheng score and Tada score. Patients' activity involving hands were assessed by both objective tools and patient-reported outcome measure while their health-related quality of life (HRQoL) was assessed by Patient- and Parent-reported Pediatric Quality of Life Inventory (PedsQL). Correlations between outcomes were analysed. Results: Overall, both parents and patients themselves reported good quality of life with mean score of 86.6% and 92.1% respectively in PedsQL. The combined surgical scores ranged from 52% good or excellent results using JSSH score to 100% good result using Cheng score. None of the outcomes on bodily structure and function showed positive correlation with patient's well-being. Negative correlation was noted in total passive range of movement, active movement and Cheng score. All patients reported no activity restriction. Writing test did not show significant slowing. The operated hands had significantly poorer fine motor dexterity than normal. No significant correlation is noted between activity outcomes and PedsQL. Conclusions: Outcomes on bodily structure, function and activity showed little correlation with patients' well-being after thumb polydactyly correction. It should be careful in using or analysing patient/parent-reported outcome measures on HRQoL as outcome assessment of surgical treatment of radial polydactyly.

A novel frameshift variant in BHLHA9 underlies mesoaxial synostotic syndactyly associated with postaxial polydactyly.

Mesoaxial synostotic syndactyly (MSSD) with phalangeal reduction is an uncommon congenital limb abnormality characterized by central osseous synostosis at a metacarpal level, mesoaxial reduction of the fingers, and preaxial cutaneous syndactyly in toes. In rare cases, the disease is also associated with fifth finger clinodactyly and postaxial polydactyly. It has autosomal recessive inheritance pattern caused by homozygous variants in the gene BHLHA9 mapped at chromosome 17p13.3. In the present study, a consanguineous family of Pakistani origin segregating MSSD in autosomal recessive form was characterized at clinical and genetic levels. Clinically, the diseased individuals have MSSD associated with clinodactyly and polydactyly. Homozygosity mapping followed by Sanger sequencing of BHLHA9 revealed a novel frameshift variant NM_001164405.1: c.409-409delC; p.(His137Thrfs*61) segregating with the disease phenotypes in the family. This is the second report providing evidence of association of polydactyly with MSSD caused by frameshift variant in the gene BHLHA9. The present molecular investigation will support genetic counselling of the local population carrying diseased variants.

Augmented manipulation ability in humans with six-fingered hands.

Neurotechnology attempts to develop supernumerary limbs, but can the human brain deal with the complexity to control an extra limb and yield advantages from it? Here, we analyzed the neuromechanics and manipulation abilities of two polydactyly subjects who each possess six fingers on their hands. Anatomical MRI of the supernumerary finger (SF) revealed that it is actuated by extra muscles and nerves, and fMRI identified a distinct cortical representation of the SF. In both subjects, the SF was able to move independently from the other fingers. Polydactyly subjects were able to coordinate the SF with their other fingers for more complex movements than five fingered subjects, and so carry out with only one hand tasks normally requiring two hands. These results demonstrate that a body with significantly more degrees-of-freedom can be controlled by the human nervous system without causing motor deficits or impairments and can instead provide superior manipulation abilities.

Long-Term Clinical and Radiographic Follow-Up of Preaxial Polydactyly Reconstruction.

PURPOSE: The purpose of the study was to determine the long-term results of preaxial polydactyly reconstruction through evaluating strength, range of motion, pain, arthritis, and functional outcomes. METHODS: Patients having preaxial polydactyly reconstruction 15 to 60 years ago completed the Disabilities of the Arm, Shoulder, and Hand (DASH) and the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE) Computer Adaptive Test (CAT). Aggregate scores were compared with those of the general population. Patients completed a clinical evaluation comprising grip strength, pinch strength, side pinch strength, and range of motion. Mean strength and range of motion were compared with the contralateral extremity. Patients had radiographs of the reconstructed thumb to evaluate for arthritis. RESULTS: Twenty-five patients, comprising 27 surgical reconstructions, completed patient-reported outcomes questionnaires, and 13 reconstructions underwent clinical and radiographic evaluation. The median follow-up was 36 years. The most common Flatt-Wassel classification was type IV. The mean DASH score was 3.7, similar to the general population mean of 10.1 (SD, 14.5). The mean PROMIS UE CAT score was 51.5, similar to the general population mean of 50 (SD, 10.0). The mean pinch strength, side pinch strength, and grip strength did not differ significantly from the contralateral extremity. There was significantly decreased range of motion at the interphalangeal joint. No patient had pain in the thumb or hand on clinical evaluation. A minority of patients developed radiographic evidence of interphalangeal joint arthritis (15.4%). Nearly half of patients, 46.2%, had angular deformity. CONCLUSIONS: Preaxial polydactyly reconstruction patients have functional outcomes similar to the general population, despite decreased range of motion at the interphalangeal joint. Patients have maintained pinch strength, side pinch strength, and grip strength. Radiographic findings of arthritis were seen in 15% of patients at follow-up but none of these patients had associated pain. Late angular deformity developed in nearly half of patients, and this highlights the importance of close follow-up until skeletal maturity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Foot Function in Patients With Surgically Treated Preaxial Polydactyly of the Foot Compared With Age- and Sex-Matched Healthy Controls.

BACKGROUND:: Treatment of preaxial foot polydactyly, a duplication of the first ray, consists of excision of an extra ray, aiming to improve shoe fitting and aesthetic appearance, while maintaining foot function. Currently, the effect of excision on foot function and foot-related patient experiences is unclear. METHODS:: A cross-sectional comparison between 37 children treated for preaxial foot polydactyly and 37 age- and sex-matched healthy controls was performed. Dynamic foot function was assessed using plantar pressure measurements and static foot characteristics by physical examination. Patient-reported outcomes for foot function and footwear were evaluated, using the Oxford Ankle Foot Questionnaire for Children (score, 0-100). RESULTS:: Compared with controls, patients had significantly lower median peak pressures at the hallux (148 kPa [IQR, 98-245] vs 272 kPa [IQR, 205-381], P < .001) and significantly higher peak pressures at the second metatarsal (217 kPa [IQR, 147-338] vs 166 kPa [IQR, 141-235], P = .002) and third to fifth metatarsals (214 kPa [IQR, 147-290] vs 161 kPa [IQR, 135-235], P < .001). Additionally, patients had a more medially deviated hallux, both while seated (15 degrees (IQR, 11-20) vs 12 degrees [IQR, 10-15], P = .001) and standing (20 degrees [IQR, 15-26] vs 18 degrees [IQR, 15-20], P = .001). No significant correlation between peak pressure distribution and hallux deviation was found. Patients reported minimal problems with foot function (87.5 [IQR, 64.6-100]), but distinct problems with footwear use (50.0 [IQR, 25.0-100]). CONCLUSION:: Patients with surgically treated preaxial foot polydactyly had a substantially altered plantar pressure distribution with more lateral foot progression than healthy controls. Although an increased hallux deviation was not related to altered foot function, it seemed to be the reason for the patient-perceived problems with footwear. Level of Evidence: Level III, comparative series.

A Case of Thumb Polydactyly which Ulnar Thumb Has No Active Motion in Ring Chromosome 4.

The objective of this study was to clarify the difference in thumb deformity between our case with ring chromosome 4 and thumb polydactyly, in which ulnar side was small and had no active motion, and other cases of ring chromosome 4, by analyzing previous reports. Our case had bilateral atypical thumb polydactyly, which was classified as type 4 on the right side and type 5 on the left side, according to the Japanese Society for Surgery of the Hand: Modified International Federation of Societies for Surgery of the Hand classification. Of the 39 cases in previous reports, 20 (51.3%) had thumb deformities. Among them, 19 cases (95%) showed radial ray deficiency and only 1 case (5%) showed bilateral thumb polydactyly. Clinodactyly was seen in 5 cases (12.8%). Foot deformities were present in 6 cases (15.4%). We discussed about thumb polydactyly with and without chromosomal deformities.

Morphological and neurophysiological impairment of the nerve in type II macrodactyly.

BACKGROUND: Macrodactyly is a congenital malformation characterized by aggressive overgrowth of multiple tissues, including subcutaneous fat, nerves, and bones in digits or limbs. In type II macrodactyly, the peripheral nerve is enlarged; however, the morphological and functional characteristics of the affected peripheral nerves have rarely been evaluated. METHODS: In this research, six macrodactyly patients and three polydactyly patients (control) were studied. Pre-operative sensory nerve action potential and intra-operative nerve action potential tests were performed. The microstructure and ultrastructure of the enlarged nerves were observed and neurofilament (NF) expression was evaluated using immunofluorescent staining. RESULTS: Axon impairment of the digital nerves originating from the median nerve (MN) was observed. A compensatory reinnervation from the ulnar nerve (UN) was found in two of the six patients, and significant morphological changes were observed in the enlarged nerve. The myelinated nerve fibers decreased, the lamellar structure of the myelin sheath changed, and the density of the NFs of the unmyelinated fibers decreased. There was aberrant distribution of NFs in the macrodactylous nerve tissues. In patients with compensatory UN reinnervation, the number of myelinated and unmyelinated fibers increased to normal levels; however, the diameter of the myelinated fibers apparently decreased. CONCLUSIONS: The morphology and function of the macrodactylous enlarged nerve was impaired in type II macrodactyly patients; however, the unaffected UN partially compensated for the lost function of the affected MN under specific situations. Electrophysiological tests should be performed to determine the function of the affected nerve and surgical treatment for type II macrodactyly could be refined.

Expanding the phenotype associated with biallelic WDR60 mutations: Siblings with retinal degeneration and polydactyly lacking other features of short rib thoracic dystrophies.

Ciliopathies are disorders of the primary cilium that can affect almost all organs and that are characterized by pleiotropy and extensive intra- and interfamilial phenotypic variability. Accordingly, mutations in the same gene can cause different ciliopathy phenotypes of varying severity. WDR60 encodes a protein thought to play a role in the primary cilium's intraflagellar transport machinery. Mutations in this gene are a rare cause of Jeune asphyxiating thoracic dystrophy (JATD) and short-rib polydactyly syndrome (SRPS). Here we report on a milder and distinct phenotype in a consanguineous Pakistani pedigree with two adolescent sisters affected by retinal degeneration and postaxial polydactyly, but lack of any further skeletal or chondrodysplasia features. By targeted high-throughput sequencing of genes known or suspected to be involved in ciliogenesis, we detected a novel homozygous N-terminal truncating WDR60 mutation (c.44delC/p.Ala15Glufs*90) that co-segregated with the disease in the family. Our finding broadens the spectrum of WDR60-related phenotypes and shows the utility of broad multigene panels during the genetic work-up of patients with ciliopathies.

Association of SNP rs80659072 in the ZRS with polydactyly in Beijing You chickens.

The Beijing You chicken is a Chinese native breed with superior meat quality and a unique appearance. The G/T mutation of SNP rs80659072 in the Shh long-range regulator of GGA2 is highly associated with the polydactyly phenotype in some chicken breeds. In the present study, this SNP was genotyped using the TaqMan detection method, and its association with the number of toes was analyzed in a flock of 158 birds of the Beijing You population maintained at the Beijing Academy of Agriculture and Forestry Sciences. Furthermore, the skeletal structure of the digits was dissected and assembled in 113 birds. The findings revealed that the toes of Beijing You chickens were rich and more complex than expected. The plausible mutation rs80659072 in the zone of polarizing activity regulatory sequence (ZRS) in chickens was an essential but not sufficient condition for polydactyly and polyphalangy in Beijing You chickens. Several individuals shared the T allele but showed normal four-digit conformations. However, breeding trials demonstrated that the T allele could serve as a strong genetic marker for five-toe selection in Beijing You chickens.

Intrafamilial variability of the triphalangeal thumb phenotype in a Dutch population: Evidence for phenotypic progression over generations?

Triphalangeal thumbs (TPTs) are regularly caused by mutations in the ZRS in LMBR1. Phenotypic variability can be present in TPT-families. However, recent observations suggest an increased occurrence of severe phenotypes in the Dutch TPT-population. Therefore, the aim of this study is to investigate the progression of the clinical severity of TPT-phenotype through generations. Index patients from a Dutch TPT-population were identified. A 105C>G mutation in the ZRS has previously been confirmed in this population. Questionnaires regarding family occurrence and phenotypes were distributed. Subsequently, families were visited to validate the phenotype. Both occurrence and inheritance patterns of the TPT-phenotype were analyzed through multiple generations. One hundred seventy patients with TPT were identified from 11 families. When considering all 132 segregations (parent-to-child transmission), 54% of the segregations produced a stable phenotype, 38% produced a more severe phenotype while only 8% of the phenotype was less severe when compared to the affected parents. Overall, 71% of the index patients had a more severe phenotype compared to their great-grandparent. Although all family members share an identical mutation in the ZRS (105C>G), it does not explain the wide phenotypic range of anomalies. Our observational study provides better estimations for counseling and provides new insights in the long-range regulation of SHH by the ZRS-enhancer. In the current study, we provide evidence that the assumed variability in TPT-phenotype is not random, but in fact it is more likely that the expression becomes more severe in the next generation. Therefore, we observe a pattern that resembles phenotypic anticipation in TPT-families.

Beemer-Langer syndrome is a ciliopathy due to biallelic mutations in IFT122.

Since most short-rib polydactyly phenotypes are due to genes involved with biogenesis and maintenance of the primary cilium, this group of skeletal dysplasias was recently designated as ciliopathies with major skeletal involvement. Beemer-Langer syndrome or short-rib polydactyly type IV, was first described in 1983, and has, thus far, remained without a defined molecular basis. The most recent classification of the skeletal dysplasias referred to this phenotype as an as-yet unproven ciliopathy. IFT122 is a gene that encodes a protein responsible for the retrograde transport along the cilium; it has been associated with this group of skeletal dysplasias. To date, mutations in this gene were only found in Sensenbrenner syndrome. Using a panel of skeletal dysplasias genes, including 11 related to SRP, we identified biallelic mutations in IFT122 ([c.3184G>C];[c.3228dupG;c.3231_3233delCAT]) in a fetus with a typical phenotype of SRP-IV, finally confirmed that this phenotype is a ciliopathy and adding to the list of ciliopathies with major skeletal involvement.

Recurrent Urinary Tract Infections in a Female Child With Polydactyly and a Pelvic Mass: Consider the McKusick-Kaufman Syndrome.

A 3-year-old female child presented with a history of recurrent urinary tract infections. On general examination, polydactyly and a pelvic mass were present. An imperforate hymen was also documented on vaginal inspection. Further inquiry revealed a positive history of parental consanguinity. A magnetic resonance imaging study defined a hydrometrocolpos responsible for an obstructive cause of the recurrent urinary tract infections. In view of the above, a diagnosis of McKusick-Kaufman syndrome was made. Formal surgical repair of the imperforate hymen with hydrometrocolpos drainage resulted in complete symptom resolution. McKusick-Kaufman syndrome, its presentation, symptoms, differential diagnosis, and underlying genetics were further expanded.

Preaxial polydactyly following early gestational exposure to the smoothened agonist, SAG, in C57BL/6J mice.

BACKGROUND: While pharmacological activation of the Hedgehog (HH) signaling pathway may have therapeutic benefits for developmental and adult diseases, its teratogenic potential is of concern. The membrane molecule Smoothened (SMO) transduces HH signaling and can be acutely modulated by antagonists and agonists. The objective of the current experiments was to determine how maternal treatment with the Smo agonist, SAG, affects the developing limb. METHODS: Pregnant C57BL/6J mice received a single injection of SAG (15, 17, or 20 mg/kg, i.p.) or its vehicle on gestational day (GD) 9.25, the time of limb bud induction. Embryos were examined on GD 15 for gross dysmorphology and skeletal staining was performed to visualize the number and type of digits on the fore- and hindlimbs. Additionally, in situ hybridization was performed 4 hr after GD 9.25 SAG administration to determine SAG's effects on Gli1 and Gli2 mRNA expression. RESULTS: The most prevalent effect of SAG was the dose-dependent induction of pre-axial polydactyly; defects ranged from a broad thumb to the duplication of two finger-like digits on the preaxial side of the thumb. The highest SAG dose was effective in ca. 80% of the embryos and increased Gli1 and Gli2 mRNA expression in the limb bud, with Gli1 mRNA being the most upregulated. CONCLUSION: Preaxial polydactyly can be caused in the developing embryo by acute maternal administration of a Smo agonist that activates HH signaling. These results are consistent with the preaxial polydactyly induced in developmental disorders associated with mutations in HH signaling genes.Birth Defects Research 109:49-54, 2017. © 2016 Wiley Periodicals, Inc.

Polydactyly in Development, Inheritance, and Evolution.

The occurrence of supernumerary digits or toes in humans and other tetrapods has attracted general interest since antiquity and later influenced scientific theories of development, inheritance, and evolution. Seventeenth-century genealogical studies of polydactyly were at the beginning of an understanding of the rules of inheritance. Features of polydactyly were also part of the classical disputes on the nature of development, including the preformation-versus-epigenesis and the atavism-versus-malformation debates. In the evolutionary domain, polydactyly was used in the criticism of the gradualist account of variation underlying Darwin's theory. Today, extra digit formation plays a role in the conceptualization of gene regulation and pattern formation in vertebrate limb evolution. Recent genetic, experimental, and modeling accounts of extra digit formation highlight the existence of nongradual transitions in phenotypic states, suggesting a distinction between continuous and discontinuous variation in evolution. Unless otherwise noted, all translations are our own.