Novel spondyloepimetaphyseal dysplasia due to UFSP2 gene mutation.

Beukes hip dysplasia is an autosomal dominant disease which has to date been described only in a large South African family of Dutch origin. The patients presented with progressive epiphyseal dysplasia limited to femoral capital epiphysis and their height was not significantly reduced. A unique variant of the ubiquitin-fold modifier 1 (Ufm1)-specific peptidase 2 (UFSP2) gene (c.868T>C) has been reported in all individuals from Beukes family with clinical and radiological diagnosis of Beukes hip dysplasia. Three individuals, propositus, mother, and grandmother, presented with short stature, joint pain, genu vara and a novel spondyloepimetaphyseal dysplasia involving epiphyses predominantly at hips, but also at knees, ankles, wrists and hands, associated with variable degrees of metaphysis and spine involvement. Exome sequencing allowed us to identify the heterozygous variant c.1277A>C of the UFSP2 gene, leading to the missense change p.D426A, in all 3 patients. This mutation is predicted as damaging and, similarly to the mutation originally described in the Beukes family (p. Y290H), directly affects one of the catalytic residues participating in the active site of the protein. This supports the novel notion that loss of catalytic UFSP2 activity, observed in association with different mutants and already experimentally proven in vitro, may have different clinical outcomes.

Whole genome sequencing in ROHHAD trios proved inconclusive: what's beyond?

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD) is a rare, life-threatening, pediatric disorder of unknown etiology, whose diagnosis is made difficult by poor knowledge of clinical manifestation, and lack of any confirmatory tests. Children with ROHHAD usually present with rapid onset weight gain which may be followed, over months or years, by hypothalamic dysfunction, hypoventilation, autonomic dysfunction, including impaired bowel motility, and tumors of neural crest origin. Despite the lack of evidence of inheritance in ROHHAD, several studies have been conducted in recent years that have explored possible genetic origins, with unsuccessful results. In order to broaden the search for possible genetic risk factors, an attempt was made to analyse the non-coding variants in two trios (proband with parents), recruited in the Gaslini Children's Hospital in Genoa (Italy). Both patients were females, with a typical history of ROHHAD. Gene variants (single nucleotide variants, short insertions/deletions, splice variants or in tandem expansion of homopolymeric tracts) or altered genomic regions (copy number variations or structural variants) shared between the two probands were searched. Currently, we have not found any potentially pathogenic changes, consistent with the ROHHAD clinical phenotype, and involving genes, regions or pathways shared between the two trios. To definitively rule out the genetic etiology, third-generation sequencing technologies (e.g., long-reads sequencing, optical mapping) should be applied, as well as other pathways, including those associated with immunological and autoimmune disorders, should be explored, making use not only of genomics but also of different -omic datasets.

Whole exome sequencing approach to childhood onset familial erythrodermic psoriasis unravels a novel mutation of CARD14 requiring unusual high doses of ustekinumab.

BACKGROUND: Autosomal dominant gain of function mutations in caspase recruitment domain family member 14 (CARD14) is a rare condition associated with plaque-type psoriasis, generalized pustular psoriasis, palmoplantar pustular psoriasis and pityriasis rubra pilaris. Recently, a new CARD14 -associated phenotype defined as CAPE (CARD14-associated papulosquamous eruption) with clinical features of both psoriasis and pityriasis rubra pilaris was reported. We describe a family carrying a novel heterozygous mutation in CARD14 gene, with childhood-onset erythrodermic psoriasis requiring an unusual extremely high dose (up to 2 mg/kg every 8 weeks) of ustekinumab to achieve disease remission. CASE PRESENTATION: We describe a large family with three pairs of twins presenting a clinical phenotype characterized by childhood-onset erythrodermic psoriasis; in some family members is also reported psoriatic arthritis. The two probands presented poor clinical response to topic and systemic therapy with antihistamine, steroid, retinoids, cyclosporine and etanercept. After exclusion of the most common genes associated to autoinflammatory diseases (IL36RN, IL1RN, MVK, TNFRSF1A, NLRP3, NLRP12, MEFV, NOD2, PSMB8, PSTPIP1, LPIN2) we approached a new gene search by subjecting to Whole Exome Sequencing (WES) analysis five members of the family. A novel heterozygous mutation (c.446 T > G, leading to the missense amino acid substitution p.L149R) in the exon 4 of the CARD14 gene was identified in all affected members. Increasing dosages (up to 2 mg/kg every 8 weeks) of ustekinumab, a human monoclonal antibody targeting interleukin-12 (IL-12) and interleukin-23 (IL-23), allowed the complete control of the clinical manifestations, with an evident reduction of circulating Th17 and Th22 CD4+ T cell subsets. CONCLUSIONS: We describe the association of mutations of the CARD14 gene with an erythrodermic psoriasis pedigree, underlying the necessity to investigate CARD14 mutations in childhood-onset psoriasis cases and confirming the presence of CARD14 causative mutations also in erythrodermic psoriasis form, as recently reported. Also in pediatric age, ustekinumab represents a powerful therapeutic option for this rare condition, that is usually refractory to other treatments. In young children, high and frequent dosages allowed a complete control of the clinical manifestations without any severe side effects, with a long-term follow-up.