Familial Vitamin D-dependent rickets Type 2A: A report of two cases with alopecia and oral manifestations

Abstract

Rickets is a metabolic bone disease that develops as a result of inadequate mineralization of growing bone due to disruption of calcium, phosphorus and/or Vitamin D metabolism. In addition, several rare genetic causes of rickets have also been described, which can be divided into two groups. The first group consists of genetic disorders of Vitamin D biosynthesis and action, such as Vitamin D-dependent rickets Type 1A, Type 1B, Type 2A (VDDR2A) and Type 2B. The second group involves genetic disorders of excessive renal phosphate loss (hereditary hypophosphatemic rickets). VDDR2A is a rare autosomal recessive disorder caused by mutation in the Vitamin D receptor gene, leading to end-organ resistance to 1,25(OH)2 Vitamin D3. It clinically represents growth retardation presenting in the 1st year of life and frequently associated with alopecia totalis, which differentiates it from VDDR Type 1. Due to target organ resistance, its response to Vitamin D is poor. We report two cases of familial VDDR2A, with alopecia and oral manifestations.

Prevalence of oral manifestations of hypophosphatemic rickets in patients treated in a Peruvian Pediatric Hospital

“…In the present study, a case of a supernumerary tooth was observed in an 8-year-old boy, which coincides with a case described by Thakur. 43 Regarding dental caries, this was the pathology with the highest frequency, similar to what has been reported in other studies, such as the one conducted by Rabbani et al 23…”

Vitamin D dependent rickets type 2: a case-based review of patient with alopecia and rickets

“…4 Additionally, genetic causes of rickets (hereditary rickets) are rare, accounting for about 13% of total rickets. 5 The comprehensive nutrition survey, by ministry of health and family welfare (GOI), states that the prevalence of vitamin D deficiency as defined by adolescents' level of 25OHD <12 ng/ml, has been found to be 14% among children aged 1-4 years ,18% among school aged children (5-9 years) and 24% among adolescent. 6 As there is a high prevalence of nutritional rickets, another aetiology of rickets is not frequently thought of.…”

“…1,12 Prithi et al, Thakur et al, Azemi et al and Aunuwar et al and our case has alopecia. 3,5,10,12 Few of the authors reported regarding enamel hypoplasia. Prithi et al and Thakur have reported about enamel hypoplasia as mentioned in Table 3.…”

“…Prithi et al and Thakur have reported about enamel hypoplasia as mentioned in Table 3. 3,5 The dental changes consist of root resorption, hypoplasia, dentin abnormalities and enlarged pulp chamber in an orthopantomogram. 14 Various laboratory changes of hereditary rickets are mentioned in Table 2 and 3.…”

“…The management of VDDR type 2 consists of a high dose of calcitriol (1-6 microgm/day in two divided doses) along with 1000 mg of elemental calcium daily. 1,5 In the case of severe hypocalcemia, patients may require intravenous calcium gluconate to safeguard patients from the dreaded complications of hypocalcemia. Although the response to therapy is suboptimal, as in VDDR type 2 patient has end organ resistance to the active form of vitamin D.…”