ABSTRACT
A male patient aged 1 year and 8 months with type 2 spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL2) was reported. The clinical characteristics included short stature, flat middle face, hypotonia, limb joint relaxation, hyperextension of metacarpophalangeal articulation, etc. In addition, the patient had a history of congenital laryngeal stridor. Thus, SEMDJL2 was determined according to the above symptoms and medical history. Sanger sequencing showed that the child carried a c.443C>T missense mutation in the KIF22 gene, which resulted in an amino acid variation namely p.Pro148Leu. This phenotype was preliminarily determined as a pathogenic mutation. Therefore, it is suggested that next-generation sequencing genetic testing could be helpful for genetic diagnosis in children with congenital laryngeal stridor, systemic joint relaxation, and excessive joint extension.
ABSTRACT
Objective:To study the clinical and genetic characteristics of Gitelman syndrome in children.Methods:Four children diagnosed with Gitelman syndrome in the Baoding Children′s Hospital from January 2017 to October 2018 were enrolled, and their clinical data and pathogenic gene carrying status were analyzed.Results:There were 2 males and 2 females in the enrolled patients.Two children complained of short stature and 2 children were diagnosed as hypokalemia by accident.All the 4 children showed constipation, short stature, repeated hypokalemia, hyponatremia, hypochloremia, normal urinary calcium/creatinine ratio, elevated renin and angiotensin Ⅱ levels in supine position, and normal aldosterone.Three children had hypomagnesemia and 1 child had a normal blood magnesium level.All of the 4 children had a compound heterozygous mutation of SLC12A3 gene.The mutations of c. 1670-7G>A and c. 1698C>A were not reported in the literature. Conclusions:Constipation and short stature are common clinical manifestations of Gitelman syndrome in children.Typical cases show hypokalemia, hypomagnesemia, hyponatremia and hypochloremia, etc.The blood magnesium level can be normal in few children.Most children with Gitelman syndrome carry SLC12A3 compound heterozygous mutations.