Bilateral Dorsal Nail Curvature of the Thumb Distal Phalanx - A Case Report.

Congenital dorsal curvature of the distal phalanx has been previously described as 'reverse Kirner' or 'ski-jump' deformity. This report describes bilateral occurrence in the thumbs. A 13-year-old male presented with difficulty caring for his thumbnails and in picking up small objects. Examination showed dorsal curvature of the distal phalanges of both thumbs, with greater curvature of the right side. Radiographs showed wedge-shaped epiphyses and dorsal curvature without coronal plane deviation of the distal phalanges. There was objective and subjective decrease in function associated with lateral pinch and tripod grasp. The reported aetiopathogenesis for Kirner deformity cannot explain the observed dorsal curvature. The bilateral nature makes a secondary physeal cause unlikely and suggests an embryologic basis. Due to the noticeable deficits in function, operative intervention may be warranted. Level of Evidence: Level V (Therapeutic).

Camptodactyly-arthropathy-coxa vara-pericarditis syndrome and an unusual association with mitral stenosis.

BACKGROUND: Campotodactyly-artrhropathy-coxa vara-pericarditis (CACP) syndrome is a very rare autosomal recessive genetic disorder. It is characterized by flexion contracture of the fifth finger (camptodactyly); noninflammatory arthropathy; decreased angle between the shaft and the head of the femur (coxa vara) and pericarditis. Its association with mitral stenosis has not yet been reported. Hereby we report this unique association with CACP syndrome. CASE: An eleven-year-old girl presented with non-productive cough, dyspnea, and orthopnea. She was diagnosed CACP syndrome at the age of seven and a biallelic frameshift mutation in the PRG4 gene was determined. The physical examination revealed pectus excavatum, camptodactyly, genu valgum, tachypnea and orthopnea. The functional capacity was NYHA III-IV. She had 2/6 soft pansystolic murmur at 4th left intercostal space and a rumbling diastolic murmur at apex. Echocardiography revealed an enlarged left atrium, severe stenotic mitral valve with a mean diastolic transmitral gradient of 22.5 mmHg, mild mitral regurgitation and mild apical pericardial effusion. The patient had mitral comissurotomy and partial pericardiectomy operation. Her post-operative transmitral gradient decreased to 6.9 mmHg and the pulmonary pressure was 30 mmHg. Her functional capacity increased to NYHA I-II. CONCLUSIONS: The main defect is the proteoglycan 4 protein which acts like a lubricant in articular and visceral surfaces. Therefore, the leading clinical feature is arthropathy. Cardiac involvement other than clinically mild pericarditis is not usually expected. Three types of proteoglycans (decorin, biglycan, and versican) are present in the mitral valve. This could be the reason of mitral valve involvement in rare cases as like ours. It is important that these patients undergo echocardiographic examination regularly.

Establishment and characterization of ZJUCHi003: an induced pluripotent stem cell line from a patient with Temple-Baraitser/Zimmermann-Laband syndrome carrying KCNH1 c.1070G > A (p.R357Q) variant.

Pathogenic variants of the KCNH1 gene can cause dominant-inherited Temple-Baraitser/Zimmermann-Laband syndrome with severe mental retardation, seizure, gingival hyperplasia and nail hypoplasia. This study established an induced pluripotent stem cell (iPSC) line using urinary cells from a girl with KCNH1 recurrent/hotspot pathogenic variant c.1070G > A (p.R357Q). The cell identity, pluripotency, karyotypic integrity, absence of reprogramming virus and mycoplasma contamination, and differential potential to three germ layers of the iPSC line, named as ZJUCHi003, were characterized and confirmed. Furthermore, ZJUCHi003-derived neurons manifested slower action potential repolarization process and wider action potential half-width than the normal neurons. This cell line will be useful for investigating the pathogenic mechanisms of KCNH1 variants-associated symptoms, as well as for evaluating novel therapeutic approaches.

Gollop-Wolfgang Complex Is Associated with a Monoallelic Variation in WNT11.

Gollop-Wolfgang complex (GWC) is a rare congenital limb anomaly characterized by tibial aplasia with femur bifurcation, ipsilateral bifurcation of the thigh bone, and split hand and monodactyly of the feet, resulting in severe and complex limb deformities. The genetic basis of GWC, however, has remained elusive. We studied a three-generation family with four GWC-affected family members. An analysis of whole-genome sequencing results using a custom pipeline identified the WNT11 c.1015G>A missense variant associated with the phenotype. In silico modelling and an in vitro reporter assay further supported the link between the variant and GWC. This finding further contributes to mapping the genetic heterogeneity underlying split hand/foot malformations in general and in GWC specifically.

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.

Split-hand/foot malformation 3 resulting from microduplications in 10q24 region in five patients from India.

Split-hand/foot malformation (SHFM) is a genetically heterogeneous congenital limb reduction defect characterized by the deficiencies of central rays of the autopod. Tandem duplications at 10q24 locus account for approximately 20% of all SHFM cases. Here, we report five affected individuals from four unrelated Indian families with SHFM3 caused by microduplication of 10q24 locus showing varied clinical presentations. This report substantiates and extends the current understanding of this rare, multifaceted, and complex condition.

A spectrum of TP63-related disorders with eight affected individuals in five unrelated families.

TP63-related disdorders broadly involve varying combinations of ectodermal dysplasia (sparse hair, hypohydrosis, tooth abnormalities, nail dysplasia), cleft lip/palate, acromelic malformation, split-hand/foot malformation/syndactyly, ankyloblepharon filiforme adnatum, lacrimal duct obstruction, hypopigmentation, and hypoplastic breasts and/or nipples. TP63-related disorders are associated with heterozygous pathogenic variants in TP63 and include seven overlapping phenotypes; Ankyloblepharon-ectodermal defects-cleft lip/palate syndrome (AEC), Ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome 3 (EEC3), Limb-mammary syndrome (LMS), Acro-dermo-ungual-lacrimal-tooth syndrome (ADULT), Rapp-Hodgkin syndrome (RHS), Split-hand/foot malformation 4 (SHFM4), and Orofacial cleft 8. We report on five unrelated families with 8 affected individuals in which the probands presented with varying combinations of ectodermal dysplasia, cleft lip/palate, split-hand/foot malformation, lacrimal duct obstruction, and ankyloblepharon filiforme adnatum. The clinical diagnosis involved AEC syndrome (2 patients), EEC3 syndrome (2 patients), and a yet hitherto unclassified TP63-related disorder. Sanger sequence analysis of the TP63 gene was performed revealing five different variants among which four were novel and three were de novo. The identificated TP63 variants co-segregated with the other affected individuals in the families. The abnormalities of ectoderm derived structures including hair, nails, sweat glands, and teeth should alert the physician to the possibility of TP63-related disorders particularly in the presence of orofacial clefting.

CATSHL syndrome, a new family and phenotypic expansion.

We report the case of a 12-year-old girl and her father who both had marked postnatal tall stature, camptodactyly and clinodactyly, scoliosis and juvenile-onset hearing loss. The CATSHL (CAmptodactyly - Tall stature - Scoliosis - Hearing Loss syndrome) syndrome was suspected, and molecular analysis revealed a hitherto unreported, monoallelic variant c.1861C>T (p.Arg621Cys) in FGFR3. This variant affects the same residue, but is different than, the variant p.Arg621His reported in the two families with dominant CATSHL described so far. Interestingly, peg-shaped incisors were observed in the proband, a feature never reported in CATSHL but typical of another FGFR3-related condition, LADD (Lacrimo - Auricolo - Dento - Digital) syndrome. The FGFR3 p.Arg621Cys variant seems to be a newly identified cause of CATSHL syndrome with some phenotypic overlap with the LADD syndrome.

Lethal variant in the C2A domain may cause severe SYT1-associated neurodevelopmental disorder in the newborns.

Synaptotagmin-1 (SYT1) plays a pivotal role in regulating presynaptic processes, including neurotransmitter release. SYT1 variants perturb synaptic vesicle endocytosis and exocytosis, resulting in a series of neurodevelopmental disorders defined as Baker-Gordon syndrome. Herein, we report the case of a newborn with dysmorphic facial appearance, severe hypotonia, poor feeding, gastroesophageal reflux, and an inability to eat and breathe, diagnosed with Baker-Gordon syndrome. A retrospective search was performed on a newborn with Baker-Gordon syndrome. Medical charts were reviewed, with focus on the clinical presentation, diagnostic process, and treatment outcomes. Whole-genome high-throughput DNA sequencing was performed to identify genetic variants. Whole-exome sequencing identified the likely pathogenic variant as SYT1 C.551 T > C(p.V184A). Sanger sequencing results indicated that this variant was a de novo mutation in a conservative site located in the C2A domain of the protein. The patient died at 57 days old because of severe feeding and breathing problems. Our findings of a novel lethal variant in the C2A domain of SYT1 in the youngest patient diagnosed infantile Baker-Gordon syndrome who presented with the most severe hypotonia reported to date expands the spectrum of SYT1- associated neurodevelopmental disorders.

Spontaneous improvement of bilateral clinodactyly of the little finger with trapezoidal phalanx: a case report with a 15-year follow-up.

Clinodactyly can be produced by a longitudinal epiphyseal bracket that generates either a 'delta' or 'trapezoidal' phalanx. We present a case with a 15-year follow-up of bilateral clinodactyly of the little finger, to emphasize a 'wait-and-see' approach as self-remodelling of his phalanges occurred during growth.

Delineation of the adult phenotype of Coffin-Siris syndrome in 35 individuals.

Coffin-Siris syndrome (CSS) is a rare multisystemic autosomal dominant disorder. Since 2012, alterations in genes of the SWI/SNF complex were identified as the molecular basis of CSS, studying largely pediatric cohorts. Therefore, there is a lack of information on the phenotype in adulthood, particularly on the clinical outcome in adulthood and associated risks. In an international collaborative effort, data from 35 individuals ≥ 18 years with a molecularly ascertained CSS diagnosis (variants in ARID1B, ARID2, SMARCA4, SMARCB1, SMARCC2, SMARCE1, SOX11, BICRA) using a comprehensive questionnaire was collected. Our results indicate that overweight and obesity are frequent in adults with CSS. Visual impairment, scoliosis, and behavioral anomalies are more prevalent than in published pediatric or mixed cohorts. Cognitive outcomes range from profound intellectual disability (ID) to low normal IQ, with most individuals having moderate ID. The present study describes the first exclusively adult cohort of CSS individuals. We were able to delineate some features of CSS that develop over time and have therefore been underrepresented in previously reported largely pediatric cohorts, and provide recommendations for follow-up.

Acroosteólisis y dismorfia facial: un nuevo caso de síndrome de Hajdu-Cheney / Acroosteolysis and facial dysmorphia: a new case of Hajdu-Cheney Syndrome

El síndrome de Hajdu-Cheney o síndrome acro-dento-osteo-displasia es una enfermedad rara caracterizada por osteólisis en banda de las falanges distales y dismorfia facial, entre otras manifestaciones. Describimos el caso de un varón de 45 años que consultó por dolor articular de características mecánicas en las manos, asociando dismorfia facial, alteraciones craneofaciales y deformidades digitales en telescopaje con acroosteólisis.(AU)

Hajdu-Cheney syndrome or acro-dento-osteo-dysplasia syndrome is a rare disease characterized by band osteolysis of distal phalanges and facial dysmorphia, among other manifestations. We present the case of a 45-year-old male who consulted for mechanical joint pain of both hands, facial dysmorphism, cranio-facial alterations, and digital telescoping with acroosteolysis.(AU)

Integration of EpiSign, facial phenotyping, and likelihood ratio interpretation of clinical abnormalities in the re-classification of an ARID1B missense variant.

Heterozygous ARID1B variants result in Coffin-Siris syndrome. Features may include hypoplastic nails, slow growth, characteristic facial features, hypotonia, hypertrichosis, and sparse scalp hair. Most reported cases are due to ARID1B loss of function variants. We report a boy with developmental delay, feeding difficulties, aspiration, recurrent respiratory infections, slow growth, and hypotonia without a clinical diagnosis, where a previously unreported ARID1B missense variant was classified as a variant of uncertain significance. The pathogenicity of this variant was refined through combined methodologies including genome-wide methylation signature analysis (EpiSign), Machine Learning (ML) facial phenotyping, and LIRICAL. Trio exome sequencing and EpiSign were performed. ML facial phenotyping compared facial images using FaceMatch and GestaltMatcher to syndrome-specific libraries to prioritize the trio exome bioinformatic pipeline gene list output. Phenotype-driven variant prioritization was performed with LIRICAL. A de novo heterozygous missense variant, ARID1B p.(Tyr1268His), was reported as a variant of uncertain significance. The ACMG classification was refined to likely pathogenic by a supportive methylation signature, ML facial phenotyping, and prioritization through LIRICAL. The ARID1B genotype-phenotype has been expanded through an extended analysis of missense variation through genome-wide methylation signatures, ML facial phenotyping, and likelihood-ratio gene prioritization.

Ulnar dimelia - a review of 24 cases.

Ulnar dimelia is a very rare unilateral congenital upper limb anomaly (CULA) affecting the whole extremity. Treatment remains difficult because of the complexity and multi-level involvement. Twenty-four cases with duplicated ulna, absent radius and polydactyly from seven European centres were reviewed according to a structured list of parameters. At first consultation, median age 8 months (1-178), the shoulder movement was good in 17 patients or poor in six, and the median passive elbow range of motion was 20° (0°-90°). The resting wrist position was flexed in 22/24 patients. Following stretching and splinting, elbow surgery included resection of the lateral proximal ulna in 11 patients and muscle transfers in six to improve passive movement and increase active elbow motion, respectively. Tendon transfers were performed in eight wrists and a pollicization or pseudo-pollicization in 23 patients. Overall, patients demonstrate acceptable function postoperatively. Guidelines for treatment of this severe CULA are presented.Level of evidence: IV.

Heterotopic respiratory mucosa as a potential source of ectopic Sonic hedgehog (SHH) in the development of complex radial polydactyly and ulnar dimelia.

We report eight cases of complex radial polydactyly and/or ulnar dimelia each with a fistulous lesion of heterotopic respiratory mucosa in radial-anterior skin ranging from shoulder to wrist. Although speculative, the coincidence of these rare conditions suggests a mechanistic relationship.

Congenital Upper-Limb Differences: A 6-Year Literature Review.

➤ The Oberg-Manske-Tonkin (OMT) classification of congenital hand and upper-limb anomalies continues to be refined as our understanding of the genetic and embryonic etiology of limb anomalies improves.➤ We have conducted an evaluation of graft and graftless techniques for syndactyly reconstruction; strengths and drawbacks exist for each technique.➤ Treatment for radial longitudinal deficiency remains controversial; however, radialization has shown promise in early follow-up for severe deformities.➤ Recent emphasis on psychosocial aspects of care has demonstrated that children with congenital upper-limb differences demonstrate good peer relationships and marked adaptability.

Donor Foot Morbidity Following Nonvascularized Toe Phalanx Transfer Utilizing a New Reconstruction Technique.

BACKGROUNDS: Nonvascularized toe phalanx transfer is an accepted surgical option for short and hypoplastic digits in congenital hand abnormalities. However, one of the criticisms of this technique is the donor site morbidity. The purpose of this study was to evaluate donor foot morbidity after nonvascularized toe phalanx transfer using a new donor site reconstruction technique. METHODS: We retrospectively reviewed 116 nonvascularized toe phalanx transfers in 69 children between 2001 and 2020 in whom the donor foot was reconstructed with a new technique using iliac osteochondral bone graft with periosteum. Feet treated with an isolated donor proximal phalanx of the fourth toe were selected and morbidity was assessed both subjectively and objectively at a minimum of 2 years after surgery. Motion, stability, and alignment of the metatarsophalangeal joint were clinically evaluated. The relative length of the fourth toe to the third toe was measured on a roentgenogram. The satisfaction of the parents for overall function and appearance was evaluated using a visual analog scale. RESULTS: Ninety-four operated feet in 65 patients, including 43 boys and 22 girls, were included. The right foot was evaluated in 52 patients and the left foot in 42 patients. The mean age at operation was 2 years and the mean follow-up period was 7.6 years. Motion at the metatarsophalangeal joint was good at 69% with an average extension of 45 degrees and flexion of 25 degrees. Stability and alignment were good at 95% and 84%, respectively. Only 4 toes had gross instability and 4 toes with poor alignment required revision surgery. Sixty-two toes (66%) maintained proportional length and 9 toes were graded as short. Parental satisfaction was high for appearance as well as function. CONCLUSIONS: This newly described technique of using iliac osteochondral bone graft with periosteum to reconstruct toe phalanx donors provided satisfactory results. The function and appearance of the donor foot after a nonvascularized toe phalanx transfer was well preserved. LEVEL OF EVIDENCE: Level IV; therapeutic.

Integrating whole-genome sequencing and transcriptomic findings in the diagnosis and management of Coffin-Siris syndrome.

INTRODUCTION: Although the whole-exome sequencing (WES) approach has been widely used in clinic, many rare diseases with syndromic and nonsyndromic neurological manifestations remain undiagnosed. Coffin-Siris syndrome (CSS) is a rare autosomal dominant genetic disease characterized by neurodevelopmental delay. A suspected diagnosis can be made based on the typical CSS clinical features; however, molecular genetic testing is necessary for a confirmed diagnosis. OBJECTIVES: Three CSS-like patients with negative results in the WES and chromosomal microarray analysis (CMA) were recruited in this study. METHODS: We used whole-genome sequencing (WGS) technology to sequence the peripheral blood of the three families. To further explore the possible pathogenesis of CSS, we performed RNA-sequencing (RNA-seq). RESULTS: WGS identified the three CSS patients were carrying de novo copy number variants of the ARID1B gene, which have not been reported before. RNA-seq identified 184 differentially expressed genes (DEGs), with 116 up-regulated and 68 down-regulated. Functional annotation of DEGs showed that two biological processes (immune response, chemokine activity) and two signaling pathways (cytokine-cytokine receptor interaction, chemokine activity) were highlighted. We speculated that ARID1B deficiency might trigger abnormal immune responses, which may be involved in the pathophysiologic mechanisms of CSS. CONCLUSION: Our research provided further support for WGS application in CSS diagnosis and made an investigational approach for the underlying mechanisms of CSS.