Congenital hand anomalies in Japan: a family study

Congenital Proximal Radioulnar Synostosis in an Elite Athlete–Case Report

Background and Objectives: Proximal radioulnar synostosis (PRUS) is the most frequent congenital forearm disorder, although the prevalence in the general population is rare with a few hundred cases reported. Pfeiffer, Poland, Holt–Oram, and other serious congenital syndromes contain this abnormality. Non-syndromic cases with isolated PRUS very often exhibit as SMAD6, NOG genes variants, or sex chromosome aneuploidy. A subgroup of patients with haematological abnormalities presents with HOXA11 or MECOM genes variants. Case report: We present a non-syndromic adult elite ice-hockey player with unilateral proximal radioulnar synostosis of the left forearm. In early childhood he was able to handle the hockey stick only as a right-handed player and the diagnosis was set later at the age of 8 years due to lack of supination. Cleary–Omer Type III PRUS was found on x-ray with radial head hypoplasia and mild osteophytic degenerative changes of humeroulnar joint. Since the condition had minimal impact on sports activities, surgical intervention was not considered. The player continued his ice-hockey career at the top level and joined a national team for top tournaments. Upper extremity function assessment with questionnaires and physical testing resulted in minimal impairment. The most compromised tool was the Failla score with 10 points from a total of 15. Genetic testing with Sanger sequencing revealed no significant pathogenic variant in SMAD6, NOG, and GDP5 genes. No potentially pathogenic copy number variants were detected by array-based comparative genomic hybridization. Conclusions: In the reported case, the ability of an athlete to deal with an anatomic variant limiting the forearm supination is demonstrated. Nowadays, a comprehensive approach to rule out more complex musculoskeletal impairment and family burden is made possible by evolving genetics.

Radial Longitudinal Deficiency: Severity Differences Between U.S. and Japanese Cohorts

PURPOSE

Radial longitudinal deficiency (RLD) presents on a spectrum of severity and associated diagnoses. The literature is limited in describing patient presentation without comparative data between countries. In a study comparing 2 cohorts of patients, 1 in the United States and 1 in Japan, we hypothesized that there would be a similar presentation of forearm deficiency severity, thumb hypoplasia severity, and associated syndromes between the 2 cohorts.

METHODS

Patients with RLD were identified via a comprehensive chart review at 2 pediatric hospital cohorts, 1 in the United States and 1 in Japan, capturing patients presenting over 15 years. We assessed RLD and thumb hypoplasia severity via a modified Bayne and Klug and modified Blauth classifications. The relationship between these 2 diagnoses and the presence of common medical conditions were evaluated and correlated.

RESULTS

A total of 194 Japanese patients with 290 involved extremities were compared with 107 U.S. patients with 174 involved extremities. The U.S. cohort had a significantly more severe RLD, and a higher rate of bilaterality (63% vs 50%, respectively). A total of 131 Japanese patients (68%) and 41 U.S. patients (38%) had associated medical syndromes/associations, most frequently vertebral abnormalities, anal atresia, cardiac abnormalities, tracheoesophageal fistula and/or esophageal atresia, renal agenesis and dysplasia, and limb defects (VACTERL; 46 Japanese, 14 U.S.), Holt-Oram (44 Japanese, 5 U.S.), and thrombocytopenia absent radius syndrome (0 Japanese, 12 U.S.). Correlation analysis showed that increased RLD severity was associated with increased thumb hypoplasia severity in both groups, with 95% of modified Bayne and Klug III, IV, or V patients having severely affected thumbs (type IIIb, IV, or V).

CONCLUSIONS

The U.S. patients had a more severe RLD and a higher rate of bilaterality. Japanese patients had a higher incidence of associated syndromes and radial polydactyly. Both cohorts showed that increased forearm severity was associated with more severe thumb hypoplasia.

TYPE OF STUDY/LEVEL OF EVIDENCE

Differential diagnosis/symptom prevalence study III.

Epidemiology of isolated preaxial polydactyly type I: data from the Polish Registry of Congenital Malformations (PRCM)

Background

Polydactyly represents a heterogeneous group of congenital hand and foot anomalies with variable clinical features and diverse etiology. Preaxial polydactyly type I (PPD1) is the most frequent form of preaxial polydactyly. The etiology of sporadic PPD1 remains largely unknown and the relative contribution of genetic and environmental factors is not clearly defined. The primary goals of this study are twofold: (1) to examine the epidemiology and clinical features of sporadic PPD1 in comparison to a healthy control group, and (2) to contrast the characteristics of sporadic PPD1 with familial forms of isolated polydactyly.

Methods

Among 2,530,349 live births registered in the Polish Registry of Congenital Malformations (PRCM), we identified 459 children with isolated sporadic PPD1 and 353 children with familial polydactyly, including 57 children with familial PPD1.

Results

In comparison with the matched group of 303 controls, sporadic PPD1 cases had significantly lower birth order (P = 0.01) and birthweight (P < 0.0001). Similarly, when compared to familial cases of polydactyly, lower birth order (P = 0.047) and lower birthweight (P < 0.0001) were characteristic of sporadic PPD1 cases. Moreover, our analyses suggested several additional risk factors for sporadic PPD1, including lower paternal education levels (P = 0.01), upper respiratory tract infections during the first trimester of pregnancy (P = 0.049), and maternal history of epilepsy (P = 0.01).

Conclusions

In summary, our study provides support to the hypothesis that non-genetic factors play an important role in the etiology of non-familiar PPD1.

The ski jump deformity of the distal phalanx: a new entity?

A case of a congenital hand anomaly is presented in which the distal phalanx of the little finger was curving dorsally in the sagittal plane. This may be the first reported case. A surgical approach to correct it is described.

Hypoplastic synpolydactyly as a new clinical subgroup of synpolydactyly

A large kindred which was first described in 1995 was investigated again. We present the clinical, radiological, genetic and surgical findings of the hand deformities found in homozygote individuals which we called "hypoplastic synpolydactyly". There were 125 affected (heterozygote or homozygote) people out of 245 subjects in the five last generations. We identified seven marriages of two affected people. Twelve offsprings, of these marriages had a homozygote genetic pattern and "hypoplastic synpolydactyly". From both the clinical and surgical perspectives, their hand deformity was distinctive from that of their parents. We surgically treated both hands of three individuals with this deformity. The hand deformity of these homozygotes was so complicated and distinctive that it can be evaluated as a new subgroup of synpolydactyly.

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.