Key Clinical and X-Ray Characteristics for the Diagnosis of Kenny-Caffey Syndrome Types 1 and 2

Kenny-Caffey syndrome (KCS) is a rare syndrome characterized by short stature, hypoparathyroidism, eye abnormalities, and skeletal dysplasia. Two types of KCS result from pathogenic variants in the tubulin-specific chaperone E (TBCE) gene and the family with sequence similarity 111 member A (FAM111A) gene, respectively.

In this study, we present 4 patients from three different families exhibiting facial dysmorphism, postnatal growth retardation, short stature, delayed bone age, cortical thickening and medullary stenosis of the bones, and hypoparathyroidism. Two of these cases were diagnosed with growth hormone (GH) deficiency and underwent GH therapy, highlighting the response to GH treatment in KCS. Three consanguineous cases of KCS type 1 possess a homozygous variant c.155_166del in the TBCE gene, and 1 patient with KCS type 2 has a de novo pathogenic variant c.1706G>A (p.Arg569His) in the FAM111 gene.

Our findings suggest that prenatal and postnatal growth failure is a prominent characteristic of this syndrome, with KCS types 1 and 2 showing overlapping features.