Nail-patella syndrome (NPS) is an uncommon autosomal dominant condition marked by nail dysplasia, skeletal abnormalities, and variable renal manifestations, resulting from mutations in the LMX1B gene. We report a rare case of a 23-year-old male presenting with nephrotic-range proteinuria, characteristic skeletal manifestations of NPS, and a family history of renal failure. Genetic testing identified a previously unreported heterozygous missense variant in the homeodomain of LMX1B (c.791A>C; p.Gln264Pro), supporting its pathogenicity. The absence of patellar hypoplasia in our patient highlights the phenotypic variability of NPS. This case reinforces the importance of detailed physical examination and targeted genetic testing in diagnosing nephrotic syndromes.

Congenital radial head dislocation (CRHD) is a rare elbow condition that often remains undiagnosed until adulthood due to its asymptomatic nature. In contrast, isolated traumatic radial head dislocation (TRHD) is another uncommon entity that results from an elbow injury. Given their rarity and overlapping clinical features, distinguishing CRHD from isolated TRHD, particularly in adults with a history of trauma, poses a significant diagnostic dilemma. This review aims to enhance awareness about both conditions, and it is the first to address an in-depth comparison. A novel dual-algorithm approach is proposed as well to overcome the diagnostic challenges and guide clinicians' decisions. PubMed and Scopus were searched to identify reported cases of CRHD and isolated TRHD in adults. Key aspects, including epidemiology, clinical presentation, diagnostic modalities, and treatment strategies, were analyzed. Two diagnostic algorithms were developed based on clinical and radiographic parameters. CRHD is often asymptomatic until adulthood, typically lacks a history of trauma, shows bilateral involvement, and is frequently associated with congenital abnormalities. Conversely, isolated TRHD presents acutely with pain and a restricted range of motion (ROM) post-trauma. Imaging findings are crucial to differentiate the former two entities. Treatment differs significantly; CRHD is typically managed conservatively unless symptomatic, while isolated TRHD often requires closed reduction, with surgery reserved for irreducible cases or instability. CRHD and isolated TRHD in adults are exceptionally rare, and differentiation is crucial for proper management. This review highlights the diagnostic challenges of CRHD first identified in adulthood and emphasizes the value of clinical suspicion, imaging, and individualized treatment planning. Finally, the dual-algorithm approach provides the first structured diagnostic model to assist differential diagnosis of CRHD and isolated TRHD in adults, offering a cost-effective pathway and a more comprehensive option when initial evaluation is inconclusive.

Congenital radial head dislocation (CRHD) is a rare deformity of the upper extremity that may be sporadic or genetic in origin. While most of the cases are unilateral and asymptomatic, bilateral involvement is very rare. This condition may be related to genetic syndromes such as Ehlers-Danlos and Turner syndromes, or it may appear as an isolated anomaly. The current pathology is the deterioration of the anatomical relationship between the humerus and the head of the radius due to a developmental anomaly. In our study, we present a 71-year-old male patient who experienced elbow pain during daily activities for about 2 years. Our patient has no history of trauma. He has been able to move functionally independently throughout his life. Physical examination revealed flexion, supination, and pronation limitations in the range of motion of the elbow joint. Plain radiograph (X-ray) and three-dimensional-computed tomography imaging revealed bilateral anterior radius head dislocation, capitellum hypoplasia, ovoid radial head, long radial neck, and shallow trochlear incisura. This case shows that bilateral CRHD, which is extremely rare, can be managed with minimal symptoms and can be successfully managed with conservative treatment. Reporting similar cases will contribute to a better understanding of the natural history of this rare condition and the most appropriate treatment strategies.

Congenital radial head dislocation (CRHD) is a rare orthopedic condition that frequently goes undiagnosed due to its asymptomatic presentation in early life. It is often identified incidentally during imaging studies for unrelated complaints or trauma. CRHD is often associated with inherited syndromes, emphasizing the genetic predisposition in this condition. While the majority of individuals remain asymptomatic in childhood, many may develop symptoms later in life, including joint stiffness, restricted range of motion, locking of the elbow joint, and aesthetic concerns related to elbow deformity. These delayed presentations can pose diagnostic challenges and contribute to a late diagnosis. We report the case of a previously asymptomatic patient who presented after a fall with pain in the right elbow. Radiographic imaging revealed radial head dislocation, with characteristic findings including a dysplastic joint, hypoplastic capitulum, convex radial head, and pseudoarthrosis. Further evaluation with X-rays of the contralateral elbow showed similar abnormalities, leading to a diagnosis of bilateral congenital radial head dislocation. Despite the structural abnormalities observed, the patient was managed conservatively without surgical intervention. Follow-up over a five-year period demonstrated satisfactory functional outcomes, with no significant worsening of symptoms or range of motion. This case highlights the importance of recognizing CRHD, particularly in patients who remain asymptomatic until adulthood or present following trauma. Conservative management can be an effective treatment approach in cases without severe functional impairment or pain, reinforcing the need for individualized treatment plans based on the patient's clinical presentation and functional demands.

Larsen of La Réunion Island syndrome (LRS) is an autosomal recessive condition associated with multiple large joint dislocations, clubfeet, severe dwarfism, and distinctive facial features. LRS is caused by a recurrent homozygous variant in B4GALT7 gene with a founder effect in La Réunion population. Proteoglycans (PG) that are a major component of the extracellular matrix, are composed of a core protein connected to a glycosaminoglycans side chain via a tetrasaccharide linker region. B4GALT7 encodes galactosyltransferase I, one of the enzymes involved in the biosynthesis of the linker region. Conditions caused by pathogenic biallelic variants in genes implicated in the synthesis of the tetrasaccharide linker of PG are known as linkeropathies. Prenatal features are rarely described in this group of chondrodysplasias. We present a series of 12 unpublished patients having LRS and describe the perinatal phenotype. All the patients had a prenatal growth restriction with brevity of limbs. The other features revealed by ultrasounds were increased nuchal translucency at 10-12 weeks of gestation (50 %), feet abnormalities (clubfeet or metatarsus varus) (25 %), dislocation affecting at least one large joint (elbow, knee, wrist) (25 %). Bilateral bowing of femora was noted for two fetuses. Fibular hypertrophy was noted for one fetus. Prenatal helical computed tomography (CT) performed in three pregnancies showed additional data such as bowing of the forearm bones, proximal radio-ulnar synostosis, or dislocation of large joints. Prenatal sonographic and helical CT findings led to the prenatal diagnosis of LRS in four patients. We confirm that the neonatal clinical picture of LRS has an important overlap with that reported in patients with B4GALT7 deficiency outside La Réunion Island and other linkeropathies. The core of the phenotypic spectrum combines low birth height, micromelia, hypermobility, dislocation of at least one large joint, facial features with prominent eyes, microstomia, depressed nasal bridge, and midface hypoplasia. Other clinical features include clubfeet (33%), bifid thumb in one patient, and cardiac abnormalities in two patients. Radiological findings include radio-ulnar synostosis (75%), metaphyseal flaring, precocious carpal ossification, and a Swedish key appearance of the proximal femora. Finally, we also report radiological features rarely described in B4GALT7-linkeropathies, including bowing of the femora and fibular hypertrophy. Our results confirm the phenotypic continuum of LRS within linkeropathies with some additional findings, including a high frequency of clubfeet usually described in B3GALT6-linkeropathies, the presence of congenital heart diseases usually described in B3GAT3-linkeropathies, and a high frequency of metaphyseal flaring usually reported in B3GALT6 or XITLT1-linkeropathies. This is the first study that describes the perinatal phenotype in a cohort of patients with LRS. This study can help improve the prenatal diagnosis of the linkeropathies and add this group of conditions to the differential diagnosis of chondrodysplasias with multiple dislocations. In view of the founder effect for LRS in La Réunion Island, this disease should be suspected in fetuses with growth restriction and micromelia. Thus in case of LOH which include B4GALT7 identified in SNP-array, we recommend performing a targeted Sanger sequencing for the recurrent mutation c.808C > T; p. (Arg270Cys).