THU168 PRMT7 Gene Mutation—A Rare Genetic Syndrome With Novel Endocrine Associations

Abstract

Abstract Disclosure: K. Nutakki: None. S. Nalla: None. P. Deb: None. A. Vulpala: None. Background: Causes of short stature in children include pathologic causes (genetic diseases, underlying systemic disease, or growth hormone deficiency) and non-pathological variants such as familial and constitutional short stature. Genetic causes include Turner’s syndrome, SHOX mutations, Noonan’s syndrome and Silver- Russel syndrome besides others. Homozygous/compound heterozygous mutations in Protein Arginine Methyltransferase 7 (PRMT7) can result in Short Stature, Brachydactyly, Intellectual Developmental Disability and Seizures syndrome (SBIDDS) . Here, we report a child with SBIDDS syndrome who has associated endocrine manifestations of growth hormone deficiency and primary hypothyroidism. Case report: A 9-year-old male child, twin A of dichorionic diamniotic gestation, presented to the Endocrine OPD with short stature. There was a history of developmental delay, seizure disorder and mild intellectual deficit. Excessive weight gain was observed since 4 years of age. On examination, he was short with abdominal obesity, brachydactyly, simian crease and macroglossia. Height was below 3rd centile and weight at the 97th percentile. SMR was pre-pubertal. Investigations confirmed primary hypothyroidism.GH deficiency (peak GH after clonidine stimulation was less than 4 microgram/L) and reduced IGF-I levels were also found. Twin B was noted to have a normal height percentile. In both, skeletal maturation was consistent with chronological age. Twin A was treated with rGH and levothyroxine and responded well to rGH treatment. Whole exome sequencing revealed homozygosity for PRMT7 mutation in twin A with both parents heterozygous for the same gene mutation. His twin sibling, twin B was also found to be homozygous for the mutation, but he did not display any characteristics of the syndrome. Discussion: To the best of our knowledge, this is only the second reported case of SBIDDS syndrome (PRMT7 mutation) with documented growth hormone deficiency and only case with documented primary hypothyroidism. Height gain observed over the period of rGH treatment is suggestive of a possible role of GH/IGF-I axis alterations as contributors of growth impairment in these children. PRMT7 encodes for an arginine methyltransferase, involved in several biological processes, such as DNA transcription and repairing, RNA splicing, cell differentiation. We would like to propose that children with SBIDDS syndrome may be tested for GH deficiency as part of their overall assessment. Likewise, it should be further explored if PRMT7 gene mutation testing should be recommended in a child presenting with short stature and one or more manifestations of SBIDDS syndrome. Presentation: Thursday, June 15, 2023