Ricerc@Sapienza

Friedreich's ataxia (FRDA) is usually due to a homozygous GAA expansion in intron 1 of the frataxin (FXN) gene. Rarely, uncommon molecular rearrangements at the FXN locus can cause pitfalls in the molecular diagnosis of FRDA. Here we describe a family whose proband was affected by late-onset Friedreich's ataxia (LOFA); long-range PCR (LR-PCR) documented two small expanded GAA alleles both in the proband and in her unaffected younger sister, who therefore received a diagnosis of pre-symptomatic LOFA.

We present a patient with suspected Proteus Syndrome, an overgrowth disorder associated with AKT1c.49G>A mutation. NGS analysis detected PIK3CAc.3140A>G mutation in the patient's affected tissue allowing for PROS (PIK3CA-related overgrowth spectrum) diagnosis. The overlapping clinical features in overgrowth disorders highlight the importance of molecular testing for a correct diagnosis.