RESULTS: In the present cross-sectional descriptive study, analysis of ZAP-70 expression showed that 36/110 (32.7%) patients positively expressed ZAP-70 and insignificant higher presentation in intermediate and at advanced stages as well as no correlation was seen with hematological parameters and clinical features compared with negatively ZAP-70, on the other hand, 41/110 (37.3%) were CD38+ and no significant correlation was shown with the stage at presentation, clinical characteristics (except Splenomegaly, P = 0.02) and hematological parameters. However, in combined expressions of both ZAP-70 and CD38 together, 20/110 (18.2%) were concordantly ZAP-70+/CD38+, 53/110 (48.2%) concordantly ZAP-70-/CD38- and 37/110 (33.6%) either ZAP-70+ or CD38+, and these three groups showed insignificant correlation with clinical (except Splenomegaly, P = 0.03) and hematological parameters, and the stage at presentation. Our data showed the combined analysis of these two markers, lead to classify our patients into three subgroups (either concordant positive, negative or discordant expressions) with statistically insignificant correlation with clinical presentation (except Splenomegaly), hematological parameters and stage at presentation of B-CLL patients.
OBJECTIVE: To identify the underlying genetic diagnoses in a paediatric cohort with GH or IGF-1 insensitivity using candidate gene (CGS) and whole-exome sequencing (WES) and assess factors associated with the discovery of a genetic defect.
METHODS: We undertook a prospective study of 132 patients with short stature and suspected GH or IGF-1 insensitivity referred to our centre for genetic analysis. 107 (96 GHI, 88 probands; 11 IGF-1 insensitivity, 9 probands) underwent CGS. WES was performed in those with no defined genetic aetiology following CGS.
RESULTS: A genetic diagnosis was discovered 38/107 (36%) patients (32% probands) by CGS. WES revealed 11 patients with genetic variants in genes known to cause short stature. A further 2 patients had hypomethylation in the H19/IGF2 region or mUPD7 consistent with Silver-Russell Syndrome (total with genetic diagnosis 51/107, 48% or 41/97, 42% probands). WES also identified homozygous putative variants in FANCA and PHKB in 2 patients. Low height SDS and consanguinity were highly predictive for identifying a genetic defect.
CONCLUSIONS: Comprehensive genetic testing confirms the genetic heterogeneity of GH/IGF-1 insensitivity and successfully identified the genetic aetiology in a significant proportion of cases. WES is rapid and may isolate genetic variants that have been missed by traditional clinically driven genetic testing. This emphasises the benefits of specialist diagnostic centres.