BACKGROUND: SHOX mutations have previously been described as causes of Léri-Weill dyschondrosteosis (LWD), Langer mesomelic dysplasia (LMD), and idiopathic short stature. The loss of X chromosome-Turner syndrome or mosaic 45,X/46,XX or 46,XY-also leads to the heterozygous loss of SHOX in patients with short stature only or with features similar to LWD. The aim of this study was to assess the efficacy of the targeted screening for SHOX variants, which involved different methods in the laboratory analysis of short stature. We determined the significance and positive predictive value of short stature for the detection of SHOX variants. METHODS: Targeted screening for variants in SHOX involving MLPA, sequencing, karyotyping and FISH was performed in the short stature cohort (N = 174) and control cohort (N = 91). The significance of short stature and particular characteristics for the detection of SHOX variants was determined by Fisher's exact test, and the probability of SHOX mutation occurrence was calculated using a forward/stepwise logistic regression model. RESULTS: In total, 27 and 15 variants influencing SHOX were detected in the short stature and control cohorts, respectively (p > 0.01). Sex chromosome aberrations and pathogenic CNV resulting in diagnosis were detected in eight (4.6%) and five (2.9%) patients of the short stature group and three (3.3%) and one (1.1%) individuals of the control group. VUS variants were discovered in 14 (8.0%) and 11 (12.1%) individuals of the short stature and control groups, respectively. MLPA demonstrated the detection rate of 13.22%, and it can be used as a frontline method for detection of aberrations involving SHOX. However, only mosaicism of monosomy X with a higher frequency of monosomic cells could be reliably discovered by this method. Karyotyping and FISH can compensate for this limitation; their detection rates in short stature group were 3.55% and 13.46% (N = 52), respectively. FISH proved to be more effective than karyotyping in the study as it could reveal cryptic mosaics in some cases where karyotyping initially failed to detect such a clone. We suggest adding FISH on different tissue than peripheral blood to verify sex-chromosome constitution, especially in cases with karyotypes: 45,X; mosaic 45,X/46,XX or 46,XY; 46,Xidic(Y) detected from blood; in children, where mosaic 45,X was detected prenatally but was not confirmed from peripheral blood. The correlation of short stature with the occurrence of SHOX mutations was insignificant and short stature demonstrates a low positive predictive value-15.5% as unique indicator for SHOX mutations. The typical skeletal signs of LWD, including Madelung deformity and disproportionate growth, positively correlate with the findings of pathogenic SHOX variants (p < 0.01) by Fisher's exact test but not with the findings of VUS variants in SHOX which are more prevalent in the individuals with idiopathic short stature or in the individuals with normal height.

• Klíčová slova
• FISH, Idiopathic short stature, Karyotyping, Leri-Weill dyschondrosteosis, MLPA, SHOX, Screening for mutations, Sequencing, Short stature, Turner syndrome,
• Publikační typ
• časopisecké články MeSH

Heterozygous aberrations of SHOX gene have been reported to be responsible for Léri-Weill dyschondrosteosis (LWD) and small portion of idiopathic short stature. The study was established to assess effectiveness of using phenotype 'scoring form' in patients indicated for SHOX gene defect analysis. The submitted study is based on a retrospective group of 352 unrelated patients enrolled as a part of the routine diagnostic practice and analyzed for aberrations affecting the SHOX gene. All participants were scanned for deletion/duplication within the main pseudoautosomal region (PAR1) using the multiplex ligation-dependent probe amplification (MLPA) method. The phenotype 'scoring form' is used in our laboratory practice to preselect patients for subsequent mutation analysis of SHOX gene-coding sequences. The overall detection rate was 11.1% but there was a significant increase in frequency of SHOX gene defect positive with increasing achieved score (P<0.0001). The most frequent aberration was a causal deletion within PAR1. In three probands, MLPA analysis indicated a more complex rearrangement. Madelung deformity or co-occurrence of disproportionate short stature, short forearm and muscular hypertrophy had represented the most potent markers to determine the likelihood of SHOX gene defect detection. We conclude that appliance of phenotype 'scoring form' had saved excessive sample analysis and enabled effective routine diagnostic testing.

• MeSH
• duplikace genu genetika   MeSH
• fenotyp MeSH
• genetické testování MeSH
• homeodoménové proteiny genetika   MeSH
• lidé MeSH
• multiplexová polymerázová řetězová reakce MeSH
• mutační analýza DNA metody   MeSH
• nanismus genetika   MeSH
• osteochondrodysplazie diagnóza   genetika   MeSH
• poruchy růstu diagnóza   genetika   MeSH
• protein SHOX MeSH
• retrospektivní studie MeSH
• sekvenční delece genetika   MeSH
• techniky amplifikace nukleových kyselin MeSH
• tělesná výška genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• homeodoménové proteiny MeSH
• protein SHOX MeSH
• SHOX protein, human MeSH Prohlížeč

• MeSH
• frekvence genu MeSH
• genetické asociační studie MeSH
• homeodoménové proteiny genetika   MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• mutační analýza DNA MeSH
• nanismus genetika   MeSH
• polymorfismus genetický MeSH
• promotorové oblasti (genetika) MeSH
• protein SHOX MeSH
• sekvence nukleotidů MeSH
• sekvenční delece * MeSH
• studie případů a kontrol MeSH
• vazebná nerovnováha MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• homeodoménové proteiny MeSH
• protein SHOX MeSH
• SHOX protein, human MeSH Prohlížeč