Syndromic Involvement of Patients Presenting With Congenital Upper Limb Anomalies: An Analysis of 4,317 Cases.

PURPOSE: This study investigated the patterns of syndromic involvement for patients with congenital upper limb anomalies (CULAs). We hypothesize that patients with CULAs will present with predictable syndromic patterns. METHODS: This retrospective study queried the multicenter Congenital Upper Limb Differences (CoULD) Registry. Of the 4,317 patients enrolled, 578 (13%) reported one or more syndromes. Syndromes were confirmed to be recognized by the Online Mendelian Inheritance in Man. Demographics were reviewed and compared with the full CoULD registry group. Syndromes reported by five or more patients were examined to determine the type of CULA according to Oberg/Manske/Tonkin classifications. RESULTS: Of the 578 children with one or more reported syndromes, 517 had Online Mendelian Inheritance in Man recognized syndromes (cohort A), In cohort A, 58 syndromes were each represented by a single patient within the registry. Forty-eight syndromes in cohort A were reported by two or more patients, which accounted for 461 of the total patients with reported syndromes. However, VACTERL and Poland syndromes were the most commonly reported syndromes. Patients with CULAs and syndromes frequently exhibited bilateral involvement (61%), compared with the entire CoULD group (47%) and other orthopedic (50%) and medical conditions (61%) compared with the entire CoULD group (24% and 27%, respectively). Additionally, they exhibited a lower frequency of family history of a congenital orthopedic condition (21%) or a family member with the same CULA (9%) compared with the entire CoULD group (26% and 14%, respectively). CONCLUSIONS: Associated syndromes were recorded in 578 patients (13%) in the CoULD registry as follows: 58 syndromes represented by a single patient, 48 by 2 or more patients, and 23 syndromes by 5 or more patients. Rare syndromes that are only represented by a single patient are more likely to be unknown by a pediatric hand surgeon, and consultation with a geneticist is advised. TYPE OF STUDY/LEVEL OF EVIDENCE: Differential Diagnosis/Symptom Prevalence Study IV.

Hypothesis: Symbrachydactyly.

The term symbrachydactyly has been used for the phenotype of two or three short fingers or toes, hypoplasia of the middle and distal phalanges and variable syndactyly of the affected digits. Some clinicians have extended this diagnosis to include other phenotypes, specifically cleft hand, terminal transverse limb defects, hypoplasia of the thumb and fifth finger with nubbins for fingers 2, 3, and 4 and the hand deformity of the Poland anomaly. A malformations surveillance program can identify enough affected infants to characterize a phenotype. In the Active Malformations Surveillance Program in Boston (1972-2012) among 289,365 births, all infants and fetuses with structural abnormalities were identified from reading the examination findings by the pediatricians and pathologists and the results of diagnostic tests. Liveborn and stillborn infants were included, as well as fetuses from elective terminations because of anomalies identified in prenatal testing. We present the findings in 14 infants, all liveborn, who had symbrachydactyly of one or both hands (n = 12) or feet (n = 2). We suggest restricting the term symbrachydactyly to this single phenotype to improve counseling and to focus future research on identifying the cause(s).

A Case Series of Familial ARID1B Variants Illustrating Variable Expression and Suggestions to Update the ACMG Criteria.

ARID1B is one of the most frequently mutated genes in intellectual disability (~1%). Most variants are readily classified, since they are de novo and are predicted to lead to loss of function, and therefore classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guidelines for the interpretation of sequence variants. However, familial loss-of-function variants can also occur and can be challenging to interpret. Such variants may be pathogenic with variable expression, causing only a mild phenotype in a parent. Alternatively, since some regions of the ARID1B gene seem to be lacking pathogenic variants, loss-of-function variants in those regions may not lead to ARID1B haploinsufficiency and may therefore be benign. We describe 12 families with potential loss-of-function variants, which were either familial or with unknown inheritance and were in regions where pathogenic variants have not been described or are otherwise challenging to interpret. We performed detailed clinical and DNA methylation studies, which allowed us to confidently classify most variants. In five families we observed transmission of pathogenic variants, confirming their highly variable expression. Our findings provide further evidence for an alternative translational start site and we suggest updates for the ACMG guidelines for the interpretation of sequence variants to incorporate DNA methylation studies and facial analyses.

The variability of SMARCA4-related Coffin-Siris syndrome: Do nonsense candidate variants add to milder phenotypes?

SMARCA4 encodes a central ATPase subunit in the BRG1-/BRM-associated factors (BAF) or polybromo-associated BAF (PBAF) complex in humans, which is responsible in part for chromatin remodeling and transcriptional regulation. Variants in this and other genes encoding BAF/PBAF complexes have been implicated in Coffin-Siris Syndrome, a multiple congenital anomaly syndrome classically characterized by learning and developmental differences, coarse facial features, hypertrichosis, and underdevelopment of the fifth digits/nails of the hands and feet. Individuals with SMARCA4 variants have been previously reported and appear to display a variable phenotype. We describe here a cohort of 15 unrelated individuals with SMARCA4 variants from the Coffin-Siris syndrome/BAF pathway disorders registry who further display variability in severity and degrees of learning impairment and health issues. Within this cohort, we also report two individuals with novel nonsense variants who appear to have a phenotype of milder learning/behavioral differences and no organ-system involvement.

Pattern of congenital hand anomalies at a tertiary plastic surgery service in South-Western Nigeria: A 10-year, cross-sectional retrospective review.

CONTEXT: Although congenital hand anomalies are among the more common musculoskeletal anomalies worldwide, we do not know its prevalence in our practice. AIMS: The aim of the study was to determine the pattern of congenital hand anomalies presenting to our tertiary plastic surgery outpatient service in South-Western Nigeria. MATERIALS AND METHODS: This is a cross-sectional retrospective analysis of outpatient cases of congenital hand anomalies presenting over a 10-year period. Descriptive and inferential statistics were performed using frequencies, Student's t-test and Chi-square as appropriate. The data were analysed using IBM SPSS Statistics 23.0. The statistical significance value was set at P < 0.05. RESULTS: One hundred and twenty-two cases were identified. The highest number of cases was seen in the year 2012, 23 patients (19.3%). There was a male preponderance of 66 patients (55.1%). Thirty-two patients (26.2%) presented as neonates and 36 (29.5%) as infants. Bilateral anomalies were seen in 67 patients (54.9%). The most common anomaly was failure of differentiation, 88 patients (72.1%) followed by duplication, 26 patients (21.3%). Syndactyly with 43 patients (35.2%) was the most common anomaly under failure of differentiation. No significant associations were found between the type of anomaly and gender or laterality. CONCLUSIONS: Syndactyly was the most common congenital hand anomaly in this study. There was a preponderance of bilateral involvement in both syndactyly and polydactyly.

Multiple synostoses syndrome: Clinical report and retrospective analysis.

Multiple synostoses syndrome (SYNS1; OMIM# 186500) is a rare autosomal dominant disorder reported in a few cases worldwide. We report a Chinese pedigree characterized by proximal symphalangism, conductive hearing loss, and distinctive facies. We examined the genetic cause and reviewed the literature to discuss the pathogeny, treatment, and prevention of SYNS1. Audiological, ophthalmological, and radiological examinations were evaluated. Whole-exome sequencing (WES) was performed to identify mutations in the proband and her parents. Sanger sequencing was used to verify the results for the proband, parents, and grandmother. The literature on the genotype-phenotype correlation was reviewed. The patient was diagnosed with multiple synostoses syndrome clinically. WES and bioinformatic analysis revealed a novel missense mutation in the NOG gene, c.554C>G (p.Ser185Cys), cosegregated in this family. The literature review showed that the phenotype varies widely, but the typical facies, conductive hearing loss, and proximal symphalangism occurred frequently. All reported mutations are highly conserved in mammals based on conservation analysis, and there are regional hot spots for these mutations. However, no distinct genotype-phenotype correlations have been identified for mutations in NOG in different races. Regular systematic examinations and hearing aids are beneficial for this syndrome. However, the outcomes of otomicrosurgery are not encouraging owing to the regrowth of bone. This study expanded the mutation spectrum of NOG and is the first report of SYNS1 in a Chinese family. Genetic testing is recommended as part of the diagnosis of syndromic deafness. A clinical genetic evaluation is essential to guide prevention, such as preimplantation genetic diagnosis.

Polydactyly a review and update of a common congenital hand difference.

PURPOSE OF REVIEW: The purpose of this review is to describe various forms of hand polydactyly and their different treatment approaches. Hand polydactyly is commonly classified as ulnar (small finger) or radial (thumb). Polydactyly can be sporadic, genetic, and/or associated with syndromic conditions. RECENT FINDINGS: Both ulnar and radial polydactyly can be surgically treated to optimize hand aesthetics and function. Timing of surgery is based on multiple factors, most notably including safety of anesthesia and socialization of the affected child. The pediatrician should be aware of potential associated conditions, such as chondroectodermal dysplasia or Ellis-van Creveld syndrome for ulnar polydactyly. SUMMARY: Polydactyly is a common congenital hand difference and can be broadly be classified by radial or ulnar involvement. Polydactyly warrants hand surgical referral, as surgical treatment is often indicated. Pediatricians should be aware of treatment options, as well as of commonly associated anomalies and syndromes.

[Radial club hand prevalence at Shriners Hospital-Mexico and literature review]. / Prevalencia de mano zamba radial en Hospital Shriners-México y revisión de la literatura.

INTRODUCTION: Radial club hand is characterized by radial deviation of the hand, as a result of hypoplasia or absence of the radius. MATERIAL AND METHODS: A descriptive, retrospective, cross-sectional and observational study of active patients diagnosed with radial club hand at the Shriners-Mexico Hospital was carried out. RESULTS: We studied 71 patients and 92 limbs, the prevalence was 0.08%, 64.7% were men and 35.3% women. We observed 22 patients with involvement of the right thoracic extremity, 28 left and 21 bilateral. It was found that 93% of the patients had an associated syndrome. The most common type of radial longitudinal dysplasia was type 1. 58 limbs did not have a thumb. The State of Mexico is the most affected and 91.6% had a guardian with maximum high school education.

INTRODUCCIÓN: La mano zamba radial congénita se caracteriza por la desviación radial de la mano como resultado de hipoplasia o ausencia del radio. MATERIAL Y MÉTODOS: Se realizó un estudio descriptivo, retrospectivo, transversal y observacional de los pacientes activos con diagnóstico de mano zamba radial. RESULTADOS: Se estudiaron 71 pacientes y 92 extremidades, la prevalencia en nuestro hospital fue de 0.08%, 64.7% fueron hombres y 35.3% mujeres. Se observaron 22 pacientes con afectación de la extremidad torácica derecha, 28 de la izquierda y 21 pacientes bilateral. Se encontró que 93% de los pacientes presentaban un síndrome asociado. El tipo de displasia longitudinal radial más común fue la tipo I. Cincuenta y ocho extremidades no contaban con pulgar. El Estado de México es el más afectado y 91.6% contaban con un responsable tutelar con escolaridad máxima de preparatoria.

Prevalence of the Linburg-Comstock variation through clinical evaluation.

INTRODUCTION: Linburg-Comstock variation, the tendinous interconnection between flexor pollicis longus and flexor digitorum profundus, is known to have a wide frequency range. Its prevalence is reported with a range of 13-66%. The aim of the study was to assess this variation in general population and to correlate it with gender and side. MATERIAL AND METHODS: This prospective study included 215 subjects (82 males and 133 females). Two clinical tests were conducted to diagnose the variation and to detect any related symptomatology. The primary outcome was set to be the prevalence of Linburg-Comstock variation. Secondary outcomes were defined as gender-based prevalence, side-based prevalence, and Linburg-Comstock variation prevalence association with gender and side. RESULTS: Linburg-Comstock variation was clinically diagnosed in 130 (60.47%) participants. Unilateral and bilateral prevalence were of 17.21% and 43.26%, respectively, yielding a statistically significant difference. Right-sided and left-sided presence were calculated at 7.44% and 9.77%. Bilateral prevalence was statistically more common in females. Right-sided variation was found to be more frequent in males while left-sided variation was more prevalent in females. The index finger was the most commonly involved with prevalence of 91.03%. Symmetry was noted in 67.74% of subjects. CONCLUSION: The results of our study demonstrated a relatively high prevalence of the Linburg-Comstock variation in Serbian population. We noted a few unusual cases and this finding point to the existence of the broader spectrum of Linburg-Comstock variation, and complexity of the flexor apparatus of the hand, so, further investigations about this topic are needed to improve our knowledge. Due to the possibility of false-positive result during clinical testing we suggest to use expanded clinical method.

Characterization of Hand Anomalies Associated With Möbius Syndrome.

PURPOSE: To investigate the distinguishing morphological characteristics of the upper extremities in children with Möbius syndrome. METHODS: Twenty-seven involved extremities in 14 patients with a diagnosis of Möbius syndrome were identified at 2 institutions. Medical records, radiographs, and clinical photographs were evaluated. Congenital hand differences were classified according to the Oberg, Manske, and Tonkin classification, and hands with symbrachydactyly were classified by the Blauth and Gekeler classification. The presence of other congenital anomalies was catalogued. RESULTS: There was bilateral involvement in 93% of patients with congenital hand anomalies. Twelve patients demonstrated congenital hand anomalies and 2 patients had been diagnosed with arthrogryposis. Among the 12 patients with congenital hand anomalies, 21 hands were classifiable as symbrachydactyly by the Oberg, Manske, and Tonkin classification and could be categorized by the Blauth and Gekeler classification. Short finger type was the most common subtype of symbrachydactyly, present in 13 hands. Eleven of these 13 patients (85%) were primarily affected on the radial side of the hand. Proximal arm involvement was identified in 2 patients with symbrachydactyly, both of whom had Poland syndrome and an absent pectoralis major. CONCLUSIONS: Symbrachydactyly in Möbius syndrome differs from the typical presentation of symbrachydactyly. Characteristically, there is a bilateral presentation with a strong predilection for radially based brachydactyly. These described characteristics may help the hand surgeon appropriately assess patients, especially those with radial-sided symbrachydactyly. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Prevalencia de mano zamba radial en Hospital Shriners-México y revisión de la literatura / Radial club hand prevalence at Shriners Hospital-Mexico and literature review

Resumen: Introducción: La mano zamba radial congénita se caracteriza por la desviación radial de la mano como resultado de hipoplasia o ausencia del radio. Material y métodos: Se realizó un estudio descriptivo, retrospectivo, transversal y observacional de los pacientes activos con diagnóstico de mano zamba radial. Resultados: Se estudiaron 71 pacientes y 92 extremidades, la prevalencia en nuestro hospital fue de 0.08%, 64.7% fueron hombres y 35.3% mujeres. Se observaron 22 pacientes con afectación de la extremidad torácica derecha, 28 de la izquierda y 21 pacientes bilateral. Se encontró que 93% de los pacientes presentaban un síndrome asociado. El tipo de displasia longitudinal radial más común fue la tipo I. Cincuenta y ocho extremidades no contaban con pulgar. El Estado de México es el más afectado y 91.6% contaban con un responsable tutelar con escolaridad máxima de preparatoria.

Abstract: Introduction: Radial club hand is characterized by radial deviation of the hand, as a result of hypoplasia or absence of the radius. Material and methods: A descriptive, retrospective, cross-sectional and observational study of active patients diagnosed with radial club hand at the Shriners-Mexico Hospital was carried out. Results: We studied 71 patients and 92 limbs, the prevalence was 0.08%, 64.7% were men and 35.3% women. We observed 22 patients with involvement of the right thoracic extremity, 28 left and 21 bilateral. It was found that 93% of the patients had an associated syndrome. The most common type of radial longitudinal dysplasia was type 1. 58 limbs did not have a thumb. The State of Mexico is the most affected and 91.6% had a guardian with maximum high school education.

Epidemiological and Clinical Aspects of Cleft Hand: Case Series From a Tertiary Public Hospital in São Paulo, Brazil.

Background: Cleft hand is a rare and congenital deformity that affects hands and feet and can be associated with other malformations. The objective was to evaluate the epidemiological and clinical aspects of cleft hand patient in a case series. Methods: Baseline characteristics associated with this deformity, such as sociodemographic characteristics, affected upper limb side, family history, clinical manifestations, and the degree of deficiency according to Barsky, Manske and Halikis, and Valenti classifications, were analyzed in 38 patients treated in the Department of Orthopedic Surgery of the Irmandade da Santa Casa de Misericórdia de São Paulo, Brazil. Results: A predominance of typical hands as classified by Barsky, types II and IV by Manske and Halikis, and type IV by Valenti was found. A high frequency of typical cases (55.3%), as defined by Barsky, had a positive family history (P = .031) and were associated with other clinical manifestations (44.7%), when compared with atypical cleft hand patients (P < .001). Conclusion: In our study, there were more typical cleft hands than atypical, and they were more commonly associated with family history and other clinical manifestations.

Congenital anomalies of digits - a clinical-epidemiological study of 301 patients.

INTRODUCTION: Congenital anomalies of digits (CAD) can occur as isolated malformations, in combination with other malformation of the limbs, or as part of a genetic syndrome. The purpose of this work is to provide an overview of CAD, on morphological, genetic and epidemiological basis. PATIENTS AND METHODS: We conducted a retrospective analysis of a cohort of 301 patients with CAD. Following the Swanson classification, the list of anomalies under study included: adactyly and oligodactyly, syndactyly and symphalangism, polydactyly, macrodactyly, amniotic bands syndrome, and generalized skeletal anomalies. RESULTS: In Bihor County, Romania, the Department of Medical Genetics recorded 4916 patients with congenital anomalies (2.03% out of 241 601 live newborns) between 1984 and 2018. Of these, 301 (6.1%) patients had CAD. The prevalence of CAD was 1:800 living newborns. The most common CAD were polydactyly, followed by syndactyly, brachydactyly, adactyly and oligodactyly. Upper extremities were four times more frequently affected than lower extremities, while both upper and lower extremities were affected in a quarter of all cases. CAD were isolated in 64% of patients, while 14% were associated with other anomalies of the extremities and 22% were associated with recognized genetic syndromes. CONCLUSIONS: Our study, by its size and the long period of clinical observation, provides opportunities to generalize and compare our data with similar studies, offering the possibility for improved knowledge of the epidemiology of CAD and potential improvements in genetic counseling.

A multidisciplinary review of triphalangeal thumb.

Despite being a rare congenital limb anomaly, triphalangeal thumb is a subject of research in various scientific fields, providing new insights in clinical research and evolutionary biology. The findings of triphalangeal thumb can be predictive for other congenital anomalies as part of an underlying syndrome. Furthermore, triphalangeal thumb is still being used as a model in molecular genetics to study gene regulation by long-range regulatory elements. We present a review that summarizes a number of scientifically relevant topics that involve the triphalangeal thumb phenotype. Future initiatives involving multidisciplinary teams collaborating in the field of triphalangeal thumb research can lead to a better understanding of the pathogenesis and molecular mechanisms of this condition as well as other congenital upper limb anomalies.

Polydactyly, postaxial, type B.

BACKGROUND: Postaxial polydactyly, type B is the most common type of polydactyly. The vestigial sixth finger is attached by a narrow neurovascular pedicle to the lateral aspect of the hand or foot at the level of the metacarpal-phalangeal joint or the metatarsal-phalangeal joint. The occurrence of this type of polydactyly varies among racial groups, by sex and sidedness. Postaxial polydactyly, type A is a fully developed extra digit on the lateral aspect of the hand or foot with a bifid fifth or sixth metacarpal/metatarsal and is much less common. METHODS: In a malformations surveillance program, the frequency in racial groups, sex ratio and the frequency of other anomalies can be established. RESULTS: Five hundred forty-five affected infants were identified from 1972 to 2012 in the surveillance of 289,365 liveborn and stillborn infants and elective terminations because of fetal anomalies detected prenatally. Postaxial polydactyly, type B was an isolated anomaly in 95% of the affected newborns. There were more affected males than females. Black infants were affected more often than White infants: 0.91/100 vs. 0.035/100 infants. The dangling extra digit was much more common in the hands than in the feet. CONCLUSIONS: Postaxial polydactyly, type B is almost always an isolated, mild malformation with no medical significance. Postaxial polydactyly, types B and A occurred in several infants, suggesting that either the underlying mutation(s) can cause both types of postaxial polydactyly or that some affected infants have more than one mutation. Autosomal dominant inheritance with variable expressivity is postulated.

Richieri-Costa-Pereira syndrome: Expanding its phenotypic and genotypic spectrum.

Richieri-Costa-Pereira syndrome is a rare autosomal recessive acrofacial dysostosis that has been mainly described in Brazilian individuals. The cardinal features include Robin sequence, cleft mandible, laryngeal anomalies and limb defects. A biallelic expansion of a complex repeated motif in the 5' untranslated region of EIF4A3 has been shown to cause this syndrome, commonly with 15 or 16 repeats. The only patient with mild clinical findings harbored a 14-repeat expansion in 1 allele and a point mutation in the other allele. This proband is described here in more details, as well as is his affected sister, and 5 new individuals with Richieri-Costa-Pereira syndrome, including a patient from England, of African ancestry. This study has expanded the phenotype in this syndrome by the observation of microcephaly, better characterization of skeletal abnormalities, less severe phenotype with only mild facial dysmorphisms and limb anomalies, as well as the absence of cleft mandible, which is a hallmark of the syndrome. Although the most frequent mutation in this study was the recurrent 16-repeat expansion in EIF4A3, there was an overrepresentation of the 14-repeat expansion, with mild phenotypic expression, thus suggesting that the number of these motifs could play a role in phenotypic delineation.

Congenital absence of the palmaris longus muscle: A meta-analysis comparing cadaveric and functional studies.

The aim of our paper was to provide comprehensive data on the prevalence of absence of palmaris longus muscle (PLM) and its anatomical characteristics and conduct two separate meta-analyses comparing cadaveric and functional studies while identifying variation among different ethnic groups. An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included prevalence of absence of PLM among subjects, ethnicity, laterality, side, and gender. Our main findings revealed that the absence of PLM is more frequently reported in functional studies. Moreover, functional tests likely overestimated the absence of PLM and recommend future studies to assess the validity of functional tests and use an imaging assessment prior to excluding the use of a palmaris longus tendon graft in patients in whom a function test identified the absence of PLM.

Recommendations for Cancer Surveillance in Individuals with RASopathies and Other Rare Genetic Conditions with Increased Cancer Risk.

In October 2016, the American Association for Cancer Research held a meeting of international childhood cancer predisposition syndrome experts to evaluate the current knowledge of these syndromes and to propose consensus surveillance recommendations. Herein, we summarize clinical and genetic aspects of RASopathies and Sotos, Weaver, Rubinstein-Taybi, Schinzel-Giedion, and NKX2-1 syndromes as well as specific metabolic disorders known to be associated with increased childhood cancer risk. In addition, the expert panel reviewed whether sufficient data exist to make a recommendation that all patients with these disorders be offered cancer surveillance. For all syndromes, the panel recommends increased awareness and prompt assessment of clinical symptoms. Patients with Costello syndrome have the highest cancer risk, and cancer surveillance should be considered. Regular physical examinations and complete blood counts can be performed in infants with Noonan syndrome if specific PTPN11 or KRAS mutations are present, and in patients with CBL syndrome. Also, the high brain tumor risk in patients with L-2 hydroxyglutaric aciduria may warrant regular screening with brain MRIs. For most syndromes, surveillance may be needed for nonmalignant health problems. Clin Cancer Res; 23(12); e83-e90. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

The Prevalence of Congenital Hand and Upper Extremity Anomalies Based Upon the New York Congenital Malformations Registry.

BACKGROUND: There have been few publications regarding the prevalence of congenital upper extremity anomalies and no recent reports from the United States. The purpose of this investigation was to examine the prevalence of congenital upper extremity anomalies in the total birth population of New York State over a 19-year period utilizing the New York Congenital Malformations Registry (NYCMR) database. METHODS: The NYCMR includes children with at least 1 birth anomaly diagnosed by 2 years of age and listed by diagnosis code. We scrutinized these codes for specific upper extremity anomalies, including polydactyly, syndactyly, reduction defects, clubhand malformations, and syndromes with upper limb anomalies. We included children born between 1992 and 2010. RESULTS: There were a total of 4,883,072 live births in New York State during the study period. The overall prevalence of congenital upper extremity anomalies was 27.2 cases per 10,000 live births. Polydactyly was most common with 12,418 cases and a prevalence rate of 23.4 per 10,000 live births. The next most common anomalies included syndactyly with 627 cases affecting the hands (1498 total) and reduction defects (1111 cases). Specific syndromes were quite rare and were noted in a total of 215 live births. The prevalence of anomalies was higher in New York City compared with New York State populations at 33.0 and 21.9 per 10,000 live births, respectively. CONCLUSIONS: The NYCMR data demonstrate that congenital upper extremity anomalies are more common than previously reported. This is in large part due to the high prevalence of polydactyly. Although registries are imperfect, such data are helpful in monitoring prevalence rates over time, identifying potential causes or associations, and guiding health care planning and future research. LEVEL OF EVIDENCE: Level I-diagnostic.

Clinical study of 459 polydactyly cases in China, 2010 to 2014.

Polydactyly is one of the most common hereditary limb malformations, involving additional digits on the hands and/or feet, which is a very attractive model to appreciate clinical and genetic heterogeneity. A high level of heterogeneity in polydactyly has been identified in different regions. However, such data of the medical literatures for Asian populations are relatively limited. This study was intended to shed light on the phenotypic manifestations of polydactyly in the recruited Chinese population and to characterize the medical literature on this condition. A total of 459 well-characterized polydactyly cases from Shanghai Children's Medical Center were recruited. Their phenotypes, inheritance patterns, and clinical heterogeneity were obtained from clinical medical records. It was found that 4.8% of cases were familial and 95.2% were sporadic. The proportions of preaxial and postaxial polydactyly types were 74.7% and 25.3%, respectively. In preaxial polydactyly, type I formed the overwhelming majority (95.9%). Among the postaxial polydactyly cases, type A was most prevalent at 69.8% and type B was witnessed in 30.2% of cases. Familial and sporadic polydactyly patients mainly had unilateral presentations. A total of 583 limbs with additional digits were recorded in the 459 subjects. Upper limb involvement was more common than lower, and right hand involvement was more common than left for preaxial polydactyly, and lower limb involvement was more common than upper in postaxial polydactyly. This cohort added useful clinical/epidemiological information to the polydactyly literature in the Chinese population and highlighted its marked clinical heterogeneity.