ABSTRACT
[This corrects the article DOI: 10.1016/j.xhgg.2022.100102.].
ABSTRACT
Loss-of-function variants in PHD Finger Protein 8 (PHF8) cause Siderius X-linked intellectual disability (ID) syndrome, hereafter called PHF8-XLID. PHF8 is a histone demethylase that is important for epigenetic regulation of gene expression. PHF8-XLID is an under-characterized disorder with only five previous reports describing different PHF8 predicted loss-of-function variants in eight individuals. Features of PHF8-XLID include ID and craniofacial dysmorphology. In this report we present 16 additional individuals with PHF8-XLID from 11 different families of diverse ancestry. We also present five individuals from four different families who have ID and a variant of unknown significance in PHF8 with no other explanatory variant in another gene. All affected individuals exhibited developmental delay and all but two had borderline to severe ID. Of the two who did not have ID, one had dyscalculia and the other had mild learning difficulties. Craniofacial findings such as hypertelorism, microcephaly, elongated face, ptosis, and mild facial asymmetry were found in some affected individuals. Orofacial clefting was seen in three individuals from our cohort, suggesting that this feature is less common than previously reported. Autism spectrum disorder and attention deficit hyperactivity disorder, which were not previously emphasized in PHF8-XLID, were frequently observed in affected individuals. This series expands the clinical phenotype of this rare ID syndrome caused by loss of PHF8 function.
ABSTRACT
INTRODUCTION: About 8% of children born small for gestational age (SGA) do not reach a final height within the normal range. Recombinant human growth hormone (rhGH) has been shown to be effective in increasing the final height in children born SGA. Our objective was to identify predictive factors of final height in children born SGA treated with rhGH. MATERIALS AND METHODS: In this retrospective study, conducted in a tertiary pediatric endocrinology referral center, we recruited all patients born SGA (defined as birth length or weight <10th percentile) treated with rhGH for more than 12 months for whom final height data were available. Some patients had received gonadotropin-releasing hormone (GnRH) analog therapy. RESULTS: We included 252 patients with an average birth length of -2.0 ± 0.7 SD and birth weight of -1.7 ± 1.0 SD. After 4.6 ± 2.8 years of rhGH treatment, their height increased from -2.2 ± 0.9 SD to -1.5 ± 0.9 SD. In multivariate analysis, we identified 8 factors that predict 46% of the final height, namely, cause of SGA (p < 0.0001), GnRH analog therapy >2 years (p = 0.006), birth length (p < 0.02), height at the start of rhGH (p < 0.0001), IGF-1 level at the start of rhGH (p = 0.0002), growth velocity during the 1st year of treatment (p = 0.0002), and age and height at the onset of puberty (p < 0.0001, p = 0.0007, respectively). CONCLUSION: In this large cohort of SGA patients who had reached their final height, we were able to confirm that growth hormone increases final height in short SGA children. In addition, we identified several factors associated with a better response to growth hormone treatment.