一个短指（趾）节病家系的调查

本文报告了一个短指（趾）节病家系的调查结果。该家系属于Bell氏的遗传性短指（趾）病中的C 型,即第二、三、五指的中指节过短型畸形。经家系调查母系正常,父系四代共调查到147人中,共发现 典型病例6人（男女各3人）,经系谱资料分析,其遗传方式符合常染体外显不完全型的显性遗传规律。 关键词：短指（趾）节病,家系调查,常染体显性遗传     

一先天性多趾并指(趾)系谱分析

本文对一多趾兼有并指(趾)家系的调查分析,从Ⅰ_2开始传递,连续四代出患者14人,男7、女7,患者均属杂合体。对多指(趾)并指(趾)畸形遗传方式进行了分析讨论。     

一个短指少指（趾）节病家系的调查

多指（趾）、并指（趾）和缺指病,在人类为多 见的遗传性疾病。而短指（趾）、少指（趾）节病 (Brachyhypophalangia）则较为少见。1951年Bell 将遗传性短指（趾）分为5型[73。在A：型短指 中,以患指中间指骨变短,并可能与远节指骨相 融合为主要特征。我们调查的家系中,所有患 指（趾）都有不同程度的中节指骨、远节指骨变 短及该两节指骨相融合的现象。外观呈两节手 指畸形。与有关资料C3 ,4,6,83所论述的该病症状 相对照,认为该短指少指（趾）节病家系患者基 本符合Bell中的A,型。现将我们的调查报 告如下。     

一个短指(趾)少指(趾)节畸形家系的调查

本文报道了一短指(趾)少指(趾)节畸形苗族家系的调查结果。该家系中患者双手、双足第一指(趾)近节指(趾)骨变短粗,第二、三、四、五指(趾)中节指(趾)骨缺如,属于遗传性短指(趾)畸形的BellA-1型。患者手纹与贵州正常苗族人有较大差异。该家系父系正常,母系4代共调查75人,发现患者22人(男13人,女9人)。系谱分析表明,该畸形属常染色体显性遗传。     

指（趾）骨异常及其相关基因研究进展

指(趾)骨异常是人群中较为常见的一种遗传缺陷,一般为常染色体显性遗传,也有少数以常染色体隐性遗传的方式传递,包括四肢大范围的缺失缺陷,也包括细微的指(趾)数目、长度、解剖形态结构的变化,是由于遗传进化过程中的变异或发育过程中的不良因素(如异常子宫内环境)所致.指(趾)骨异常可以分为多指(趾)并指(趾)症(Synpolydactyly,SPD)、手足裂畸形(split-hand/split-foot malformation,SHFM)和短指(趾)(Brachydactyly,BD).本文综述了指(趾)骨异常的分类及其遗传特点,总结了指(趾)骨异常畸形相关基因的研究进展.     

双手双足并指（趾）多指（趾）多掌（？）骨畸形家系的分析

遗传性多指并指畸形国内已有报道［11.27,均 属常染色体显性遗传。我们发现了一个呈性连 锁显性遗传的双手双足并指（趾）多指（趾）多掌 （班）骨畸形的家系,现报告如下。     

一个短指（趾）节病家系的调查

本文报告了一个短指（趾）节病家系的调查结果。该家系属于Bell氏的遗传性短指（趾）病中的C 型，即第二、三、五指的中指节过短型畸形。经家系调查母系正常，父系四代共调查到147人中，共发现 典型病例6人（男女各3人），经系谱资料分析，其遗传方式符合常染体外显不完全型的显性遗传规律。 关键词：短指（趾）节病，家系调查，常染体显性遗传     

多指畸形的遗传性调查

调查了5个多指（趾）畸形的家系,在56人中有患者9人。该征的主要临床特征是：在拇指（趾）或小指（趾）的掌指（趾）上生有一赘生指（趾）,也有发育不全者只有残迹悬于皮肤蒂上。据调查统计,何氏家系与刘氏家系提示多指畸形系常染色体显性遗传。其他3个家系则与何、刘二家系相悖,究其原因,还有待于积累更丰富的资料来证实。     

多指（趾）并指（趾）畸形家系分析

多指（趾）和并指（趾）畸形症状,在人类中 是较为常见的遗传性疾病,但在人群中不同的 个体往往表现出遗传性状有很大差异。根据 Mckusick氏的研究,把多指（趾）畸形按额外指 （趾）赘生的部位分,大致可归纳为挠侧、胫侧、拇 指、食指等4种不同类型。另外对并指（趾）畸形, 根据指（趾）与指（趾）之间的部分或全部皮肤性 或骨性的联结及融合情况可分为5种类型^[2]     

人类的椎骨式、牙式、乳头式、指(趾)式证实了人猿同祖

通过对人类的椎骨式、牙式、乳头式、指（趾）式的阐述，进一步说明这些结构是生物进化过程中形成，是“人猿同祖”的有力证据。     

Two unusual types of syndactyly in the same family; Cenani-Lenz type and "new" type versus severe type I syndactyly?

Cenani-Lenz syndactyly is a very rare syndrome where the syndactyly is totally disorganized with abnormal development of pattern formation of the hand. We report here an additional case of Cenani-Lenz syndactylism in a woman who has congenital cataract and an unusual type of duplication of big toes not described so far. She had a half cousin who had an unusual new type or severe type I syndactyly. It is not clear whether these two types of syndactyly present in this family may be coincidental or not.     

A case of symbrachydactyly with oligodactyly

The term symbrachydactyly describes syndactyly accompanied by brachydactyly. Brachydactyly is seen in middle phalanges of both hands and feet and very short in length or absent. As for syndactyly it is a cutaneous type. It has always been observed unilaterally and sporadically. A familial type of this syndrome has also been reported. There have been many classifications of symbrachydactyly. Of these, Blauth classification is the most favored one. Yet these classifications have been inadequate to include many recently discovered other forms of symbrachydactyly. A three month old child was brought to the Istanbul University Genetic Research Center because of his abnormal hands and feet. He was the second child of a couple who had no kinship ties to each other. In the history of the family, there was no mention of any anomaly as such. There was a complete syndactyly involving the 3rd through the 5th fingers, partial syndactyly between the 2nd and 3rd, and the thumb was normal in the right hand. There was only one finger in the left hand. There was total syndactyly in four toes of the right foot with oligodactyly and absence of the big toe. The left foot had five toes with a complete syndactyly between the 2nd and the 3rd. Radiological observation indicated that the middle phalanges of both extremities were rudimentary or never developed. There was no osseous syndactyly. As observed in this case, oligodactylous type that is bilateral and involves both hands and feet together is very unusual. The purpose of this study is to present a rare case of this anomaly that requires a reassessment of symbrachydactyly and its traditional classifications.     

Oculo-dento-digital dysplasia (OMIM *164200). Full manifestation of the syndrome in a 9.5 year-old girl and type III syndactyly in the father

In this short report we present further evidence for the autosomal dominant pattern of inheritance with variable expressivity in the Oculo-Dento-Digital Dysplasia (OMIM * 164200). The full clinical manifestation of the syndrome was observed in a 9.5-year-old girl with contrasting mild manifestation (complete cutaneous syndactyly of fingers IV-V--type III syndactyly) in her father.     

Integration,heterochrony, and adaptation in pedal digits of syndactylous marsupials

Background  

Marsupial syndactyly is a curious morphology of the foot found in all species of diprotodontian and peramelemorph marsupials. It is traditionally defined as a condition in which digits II and III of the foot are bound by skin and are reduced. Past treatments of marsupial syndactyly have not considered the implications of this unique morphology for broader issues of digit development and evolution, and the ongoing debate regarding its phylogenetic meaning lacks a broad empirical basis. This study undertakes the first interdisciplinary characterisation of syndactyly, using variance/covariance matrix comparisons of morphometric measurements, locomotor indices, ossification sequences, and re-assessment of the largely anecdotal data on the phylogenetic distribution of tarsal/metatarsal articulations and "incipient syndactyly".     

Syndactyly of the toes

The experience gained through the management of 43 patients with syndactyly of the toes is presented. The incidence appears to be similar to that of syndactyly of the fingers. Type 1 syndactyly, or zygodactyly, always presented itself as a cosmetic problem; its correction is occasionally indicated and the procedure used is discussed. Type 2 syndactyly, or polysyndactyly, represents a functional problem and deserves surgical correction. My negative experience with the more complex procedures described for the correction of polysyndactyly is presented as well as my satisfaction with the simpler procedures. Suggestions for management are offered.     

Advances in the Molecular Genetics of Non-syndromic Syndactyly

Syndactyly, webbing of adjacent digits with or without bony fusion, is one of the most common hereditary limb malformations. It occurs either as an isolated abnormality or as a component of more than 300 syndromic anomalies. There are currently nine types of phenotypically diverse nonsyndromic syndactyly. Non-syndromic syndactyly is usually inherited as an autosomal dominant trait, although the more severe presenting types and subtypes may show autosomal recessive or X-linked pattern of inheritance. The phenotype appears to be not only caused by a main gene, but also dependant on genetic background and subsequent signaling pathways involved in limb formation. So far, the principal genes identified to be involved in congenital syndactyly are mainly involved in the zone of polarizing activity and sonic hedgehog pathway. This review summarizes the recent progress made in the molecular genetics, including known genes and loci responsible for non-syndromic syndactyly, and the signaling pathways those genetic factors involved in, as well as clinical features and animal models. We hope our review will contribute to the understanding of underlying pathogenesis of this complicated disorder and have implication on genetic counseling.     

Chromosome Abnormalities in Patients with Syndactyly

Chromosome studies on 105 patients with syndactyly included two trisomy-21 mongols, a chromatin-positive boy with 47, XXY, a chromatin-negative short girl with 45,X0 and a boy with a familial D/D translocation. Chromosome patterns were normal in the other cases which included three patients with acrocephalosyndactyly and one patient with oro-facial-digital syndrome.The incidence of chromosome abnormalies was greater than expected since syndactyly of the fingers is uncommon in the chromosome disorders.This incidence may be related to the increased maternal age (mean: 29.4 years) of the syndactyly group compared to maternal age (mean: 26.64 years) of the control group although, paradoxically, four mothers of the five patients with chromosome abnormalities were young.     

A simple method for characterising syndactyly in clinical practice

Non-syndromic syndactyly is a heterogeneous group of limb malformations involving webbing of fingers and/or toes. There are at least nine non-syndromic types described in the literature. For the clinician and the genetic counsellor not having gathered experience with this malformation, it is rather tedious to identify the correct subtype for the patient's phenotype. We therefore present a protocol for clinical use, which visualises the malformation in a graphical way and thereby simplifies typing. In addition, this protocol provides a simple documentation system for reporting clinical data for new syndactyly families. It might encourage clinicians to report families that are still unclassifed and thus, helping to extend and improve the existing classification system.     

Activities of N-Myc in the developing limb link control of skeletal size with digit separation

The developing limb serves as a paradigm for studying pattern formation and morphogenetic cell death. Here, we show that conditional deletion of N-Myc (Mycn) in the developing mouse limb leads to uniformly small skeletal elements and profound soft-tissue syndactyly. The small skeletal elements are associated with decreased proliferation of limb bud mesenchyme and small cartilaginous condensations, and syndactyly is associated with a complete absence of interdigital cell death. Although Myc family proteins have pro-apoptotic activity, N-Myc is not expressed in interdigital cells undergoing programmed cell death. We provide evidence indicating that the lack of interdigital cell death and associated syndactyly is related to an absence of interdigital cells marked by expression of Fgfr2 and Msx2. Thus, instead of directly regulating interdigital cell death, we propose that N-Myc is required for the proper generation of undifferentiated mesenchymal cells that become localized to interdigital regions and trigger digit separation when eliminated by programmed cell death. Our results provide new insight into mechanisms that control limb development and suggest that defects in the formation of N-Myc-dependent interdigital tissue may be a root cause of common syndromic forms of syndactyly.     

The skin of birds' feet: Morphological adaptations of the plantar surface

The skin of the foot provides the interface between the bird and the substrate. The foot morphology involves the bone shape and the integument that is in contact with the substrate. The podotheca is a layer of keratinized epidermis forming scales that extends from the tarsometatarsus to the toe extremities. It varies in size, shape, amount of overlap and interacts with the degree of fusion of the toes (syndactyly). A study of toe shape and the podotheca provides insights on the adaptations of perching birds. Our analysis is based on micro‐CT scans and scanning electron microscopy images of 21 species from 17 families, and includes examples with different orientations of the toes: zygodactyl (toes II and III forward), anisodactyl (toes II, III, and IV forward), and heterodactyl (toes III and IV forward). We show that in these three groups, the skin forms part of a perching adaptation that involves syndactyly to different degrees. However, syndactyly does not occur in Psittacidae that use their toes also for food manipulation. The syndactyly increases the sole surface and may reinforce adherence with the substrate. Scale shape and toe orientation are involved in functional adaptations to perch. Thus, both bone and skin features combine to form a pincer‐like foot.