Prenatal diagnosis of fibular aplasia-tibial campomelia-oligosyndactyly syndrome: Two case reports and review of the literature

A Case of Fibular Aplasia-Tibial Campomelia-Oligosyndactyly (FATCO) Syndrome Associated With Split Hand/Foot Syndrome With Long Bone Deficiency (SHFLD) and Review of the Literature

Split hand/foot malformation is a heterogeneous congenital disorder mainly presented with a median cleft of hands or/and feet. It can be associated with long bone aplasia, a syndrome also known as split hand/foot syndrome with long bone deficiency (SHFLD), which is a very rare condition. We report a very rare case of a male fetus with SHFLD syndrome combined with fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome. FATCO syndrome is also an extremely infrequent congenital limb defect by itself. Based on our review of the literature, there appears to be no other FATCO case reported in Greece.

New pathogenic variant in DLX5: New clues for a clinical spectrum from split-hand-foot malformation to fibular aplasia, tibial campomelia and oligosyndactyly

Introduction: FATCO (Fibular Aplasia, Tibial Campomelia and Oligosyndactyly) is a very infrequent skeletal dysplasia classified within the limb hypoplasia-reduction defects group whose genetic cause has not yet been identified. The advent of next-generation sequencing is enabling the diagnosis of diseases with no previously known genetic cause. Methods: We performed a thorough autopsy on a fetus whose pregnancy was legally terminated due to severe malformations detected by ultrasound. A trio exome was run to identify the genetic cause and risk of recurrence. Previous literature of similar cases was systematically searched. Results: Anatomopathological analyses revealed complete fibular aplasia, shortened and campomelic tibia, absent ankle joint, club right foot and a split foot malformation, leading to the diagnosis of FATCO. Exome sequencing showed that the female fetus carried a de novo nonsense variant in DLX5. The literature search permitted the collection of information on 43 patients with FATCO, the majority of whom were males diagnosed postnatally. In most cases, lower limbs were affected exclusively, but in 39.5% of cases the upper limbs were also affected. Conclusion: The pathologies associated with DLX5 variants encompass a wide spectrum of manifestations ranging from abnormalities exclusively in the hands and feet to long bones such as the tibia and fibula.

Genomic sequencing in a cohort of individuals with fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome

Fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome (MIM 246570) is a rare disorder characterized by specific skeletal findings (fibular aplasia, shortened or bowed tibia, and oligosyndactyly of the foot and/or hand). Typically, no other anomalies, craniofacial dysmorphism, or developmental delays are associated. Here we report three unrelated individuals with limb anomalies consistent with FATCO syndrome who have been followed clinically for 5 years. Genetic testing of previously reported individuals with FATCO syndrome has not revealed a genetic diagnosis. However, no broader sequencing approaches have been reported. We describe the results of the three individuals with FATCO syndrome from exome and genome sequencing, all of which was nondiagnostic. Our study suggests that FATCO syndrome is not the result of a simple monogenic etiology.