ESPE Abstracts

Kenny-Caffey syndrome type 2 (KCS 2) is an extremely rare autosomal dominant genetic disorder characterized by proportionate short stature, hypoparathyroidism, skeletal dysplasia and facial deformities. It is caused by variants in FAM111A gene. The clinical manifestations of KCS2 are atypical and diverse. We present two cases with KCS 2 with short stature, skeletal deformities and eye abnormalities confirmed by genetic analysis. The first patient came to our hospital due to short stature (h = - 4.8 SDS). The second patient came to our hospital due to lost weight (h = - 4.5 SDS). Both of them had hypermetropia, dysmorphic facial features, extremely proportionate short stature and normal neurodevelopment. They also had cortical thickening, medullary stenosis of the long bones X-ray and delayed closure of the anterior fontanelle. The biggest difference between these two patients is that one patient has hypoparathyroidism (hypocalcemia and inappropriately low normal parathyroid hormone) and the other patient has hyperthyroidism (with normal thyroid antibodies). Further genetic testing revealed a heterozygous missense variant in FAM111A gene (c.1706G>A). This variant has been classified as Pathogenic variant. The patient who had hypoparathyroidism was treated with calcitriol, calcium D3 and rhGH. Her serum calcium concentration improved well. Her height velocity was 6cm in 10 months of rhGH replacement. The other patient who had hyperthyroidism was treated with Thiamazole. Her thyroid function was normal after 2 months of treatment.