Ciliopathies are responsible for short stature and insulin resistance: A systematic review of this clinical association regarding SOFT syndrome.

ABSTRACT

SOFT syndrome (Short stature-Onychodysplasia-Facial dysmorphism-hypoTrichosis) is a rare primordial dwarfism syndrome caused by biallelic variants in POC1A encoding a centriolar protein. To refine the phenotypic spectrum of SOFT syndrome, recently shown to include metabolic features, we conducted a systematic review of all published cases (19 studies, including 42 patients). The SOFT tetrad affected only 24 patients (57%), while all cases presented with short stature from birth (median height -5.5SDS([-8.5]-[-2.8])/adult height 132.5 cm(103.5-148)), which was most often disproportionate (90.5%), with relative macrocephaly. Bone involvement resulted in short hands and feet (100%), brachydactyly (92.5%), metaphyseal (92%) or epiphyseal (84%) anomalies, and/or sacrum/pelvis hypoplasia (58%). Serum IGF-I was increased (median IGF-I level + 2 SDS ([-0.5]-[+ 3])). Recombinant human growth hormone (rhGH) therapy was stopped for absence/poor growth response (7/9 patients, 78%) and/or hyperglycemia (4/9 patients, 45%). Among 11 patients evaluated, 10 (91%) presented with central distribution of fat (73%), clinical (64%) and/or biological insulin resistance (IR) (100%, median HOMA-IR 18), dyslipidemia (80%), and hepatic steatosis (100%). Glucose tolerance abnormalities affected 58% of patients aged over 10 years. Patients harbored biallelic missense (52.4%) or truncating (45.2%) POC1A variants. Biallelic null variants, affecting 36% of patients, were less frequently associated with the SOFT tetrad (33% vs 70% respectively, p = 0.027) as compared to other variants, without difference in the prevalence of metabolic abnormalities. POC1A should be sequenced in children with short stature, altered glucose/insulin homeostasis and/or centripetal fat distribution. In patients with SOFT syndrome, rhGH treatment is not indicated, and IR-related complications should be regularly screened and monitored.PROSPERO registration CRD42023460876.