Advances and Challenges in Prenatal Detection and Genetic Diagnosis of Upper Limb Anomalies: Analysis of a South London and Kent Cohort.

Objective: Prenatal detection and genetic diagnosis of congenital upper limb anomalies is particularly challenging due to both anatomical and technological factors. Hereby, we present a cross-sectional description of clinical and genetic findings in a 188-patient cohort.

Method: In this retrospective study, we present 188 cases with prenatally or postnatally detected upper limb anomalies, either isolated, associated with other anomalies, or syndromic. Patients were examined in four tertiary care centers in South London and Kent from 2012 to 2023.

Results: Anomalies were prenatally detected in 158/188 patients (84%), with positional defects (37), polydactyly (34) and transverse defects (25) as the most frequent. 63/188 patients (58%) received a genetic diagnosis of aneuploidy (36), Copy Number Variant (9), or monogenic disorder (18). In 39 out of 103 prenatally tested patients (38%), this diagnosis was given prenatally, contributing to termination of the pregnancy in 23 cases.

Conclusion: Through a cross-sectional description of 188 cases with congenital upper limb anomalies, we discuss prenatal ultrasound detection (in terms of numbers and accuracy) and genetic diagnosis.