Hereditary vitamin D-resistant rickets （HVDRR） is a rare autosomal recessive disorder characterized by severe rickets, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase...Hereditary vitamin D-resistant rickets （HVDRR） is a rare autosomal recessive disorder characterized by severe rickets, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. This disorder is caused by homogeneous or heterogeneous mutations affecting the function of the vitamin D receptor （VDR）, which lead to complete or partial target organ resistance to the action of 1,25- dihydroxy vitamin D~ A non-consanguineous family of Chinese Han origin with one affected individual demonstrating HVDRR was recruited, with the proband evaluated clinically, biochemically and radiographically. To identify the presence of mutations in the VDR gene, all the exons and exon-intron junctions of the VDR gene from all family members were amplified using PCR and sequenced. The proband showed rickets, progressive alopecia, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. She also suffered from epilepsy, which is rarely seen in patients with HVDRR. Direct sequencing analysis revealed a homozygous missense mutation c.122G 〉 A （p.C41Y） in the VDR gene of the proband, which is located in the first zinc finger of the DNA-binding domain. Both parents had a normal phenotype and were found to be heterozygous for this mutation. We report a Chinese Han family with one individual affected with HVDRR. A homozygous missense mutation c.122G 〉 A （p.C41Y） in the VDR gene was found to be responsible for the patient＇s syndrome. In contrast to the results of treatment of HVDRR in other patients, our patient responded well to a supplement of oral calcium and a low dose of calcitriol.展开更多
<p> <b><span style="font-family:Verdana;">Background: </span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"&...<p> <b><span style="font-family:Verdana;">Background: </span></b><span style="font-family:;" "=""><span style="font-family:Verdana;">Globally there is a high burden of low serum vitamin D deficiency (VDD) with children being acknowledged at risk due to low vitamin D content in both breastmilk and available foods and inadequate cutaneous synthesis of vitamin D. Even in countries with abundant sunshine, vitamin D deficiency (VDD) remains a problem. There is little characterization of the status of vitamin D among infants in East Africa. This study aimed to determine the prevalence and factors associated with vitamin D deficiency among infants attending the Reproductive and Child Health (RCH) Clinic in Arusha, Tanzania. </span><b><span style="font-family:Verdana;">Methods: </span></b><span style="font-family:Verdana;">A cross-sectional study of 304 infants aged 6 weeks to 12 months was conducted at Arusha Lutheran Medical Centre (ALMC). Infants were enrolled during the warm season between November 2018 and January 2019. A pre-coded questionnaire was used to collect data on sociodemographic characteristics of the infant with consent from their caretakers. Physical examination was done for anthropometric measures and signs of rickets. Blood was drawn for assessment of serum 25-hydroxyvitamin D 25(OH)D, calcium, phosphorus and alkaline phosphate. Vitamin D deficiency was defined as 25(OH)D level below 20 ng/ml (<50 nmol/L) and Vitamin D insufficiency defined as a 25(OH)D level 20 - 30 ng/ml (50 - 75 nmol/L). Statistical </span><span><span style="font-family:Verdana;">analysis was performed using STATA 14 version and factors associated with VDD explored with multivariate analysis. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The mean serum 25(OH)D </span></span><span style="font-family:Verdana;">among infants was 34.51 ng/ml (±15.53). Vitamin D deficiency was found in 67/304 (22%) infants and Vitamin D insufficiency in 50 (16.5%) infants. Hypocalcemia was observed in 33 (10.9%) infants and clinical findings of rickets were found in 11 infants (3.6%). Factors independently associated with VDD included age < 6 months (Adjusted Odds Ratio (AOR) 1.56, 95% CI 1.19 - 4.0, p value < 0.026), serum signs of rickets and serum hypocalcemia (p-value < 0.001 and <0.002, respectively). </span><b><span style="font-family:Verdana;">Conclusion and Recommendation: </span></b><span style="font-family:Verdana;">A high prevalence of Vitamin D deficiency (22%) and insufficiency (16.5%) was observed among infants attending RCH Clinic in Arusha, Tanzania. Age < 6 months, a single serum measurement of hypocalcemia and the presence of the clinical sign of rickets were independently associated with VDD. Clinicians should actively assess for VDD and supplement with vitamin D as indicated, especially among infants < 6 months.</span></span> </p>展开更多
Hypophosphatemic vitamin D-resistant rickets or X-linked hypophosphatemia （XLH） is a rare hereditary metabolic disease manifesting marked hypophosphatemia, short stature and rickets. Its prevalence is approximately ...Hypophosphatemic vitamin D-resistant rickets or X-linked hypophosphatemia （XLH） is a rare hereditary metabolic disease manifesting marked hypophosphatemia, short stature and rickets. Its prevalence is approximately 1 in 20 000. Except early exfoliation of the teeth, there are a few oral findings of XLH described in China. Here we present two cases in one family.展开更多
基金supported by a grant from The Ministry of Science and Technology of the People’s Republic of China(National Science and Technology Major Projects for "Major New Drugs Innovation and Development" 2008ZX09312-016)National Natural Science Foundation of China (no.81070687 and 81170805)+2 种基金Beijing Natural Science Foundation (no.7121012)Scientific Research Foundation of Beijing Medical Development (no.2007-3029)National Key Program of Clinical Science (WBYZ2011-873)
文摘Hereditary vitamin D-resistant rickets （HVDRR） is a rare autosomal recessive disorder characterized by severe rickets, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. This disorder is caused by homogeneous or heterogeneous mutations affecting the function of the vitamin D receptor （VDR）, which lead to complete or partial target organ resistance to the action of 1,25- dihydroxy vitamin D~ A non-consanguineous family of Chinese Han origin with one affected individual demonstrating HVDRR was recruited, with the proband evaluated clinically, biochemically and radiographically. To identify the presence of mutations in the VDR gene, all the exons and exon-intron junctions of the VDR gene from all family members were amplified using PCR and sequenced. The proband showed rickets, progressive alopecia, hypocalcemia, hypophosphatemia, secondary hyperparathyroidism, and elevated alkaline phosphatase. She also suffered from epilepsy, which is rarely seen in patients with HVDRR. Direct sequencing analysis revealed a homozygous missense mutation c.122G 〉 A （p.C41Y） in the VDR gene of the proband, which is located in the first zinc finger of the DNA-binding domain. Both parents had a normal phenotype and were found to be heterozygous for this mutation. We report a Chinese Han family with one individual affected with HVDRR. A homozygous missense mutation c.122G 〉 A （p.C41Y） in the VDR gene was found to be responsible for the patient＇s syndrome. In contrast to the results of treatment of HVDRR in other patients, our patient responded well to a supplement of oral calcium and a low dose of calcitriol.
文摘<p> <b><span style="font-family:Verdana;">Background: </span></b><span style="font-family:;" "=""><span style="font-family:Verdana;">Globally there is a high burden of low serum vitamin D deficiency (VDD) with children being acknowledged at risk due to low vitamin D content in both breastmilk and available foods and inadequate cutaneous synthesis of vitamin D. Even in countries with abundant sunshine, vitamin D deficiency (VDD) remains a problem. There is little characterization of the status of vitamin D among infants in East Africa. This study aimed to determine the prevalence and factors associated with vitamin D deficiency among infants attending the Reproductive and Child Health (RCH) Clinic in Arusha, Tanzania. </span><b><span style="font-family:Verdana;">Methods: </span></b><span style="font-family:Verdana;">A cross-sectional study of 304 infants aged 6 weeks to 12 months was conducted at Arusha Lutheran Medical Centre (ALMC). Infants were enrolled during the warm season between November 2018 and January 2019. A pre-coded questionnaire was used to collect data on sociodemographic characteristics of the infant with consent from their caretakers. Physical examination was done for anthropometric measures and signs of rickets. Blood was drawn for assessment of serum 25-hydroxyvitamin D 25(OH)D, calcium, phosphorus and alkaline phosphate. Vitamin D deficiency was defined as 25(OH)D level below 20 ng/ml (<50 nmol/L) and Vitamin D insufficiency defined as a 25(OH)D level 20 - 30 ng/ml (50 - 75 nmol/L). Statistical </span><span><span style="font-family:Verdana;">analysis was performed using STATA 14 version and factors associated with VDD explored with multivariate analysis. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The mean serum 25(OH)D </span></span><span style="font-family:Verdana;">among infants was 34.51 ng/ml (±15.53). Vitamin D deficiency was found in 67/304 (22%) infants and Vitamin D insufficiency in 50 (16.5%) infants. Hypocalcemia was observed in 33 (10.9%) infants and clinical findings of rickets were found in 11 infants (3.6%). Factors independently associated with VDD included age < 6 months (Adjusted Odds Ratio (AOR) 1.56, 95% CI 1.19 - 4.0, p value < 0.026), serum signs of rickets and serum hypocalcemia (p-value < 0.001 and <0.002, respectively). </span><b><span style="font-family:Verdana;">Conclusion and Recommendation: </span></b><span style="font-family:Verdana;">A high prevalence of Vitamin D deficiency (22%) and insufficiency (16.5%) was observed among infants attending RCH Clinic in Arusha, Tanzania. Age < 6 months, a single serum measurement of hypocalcemia and the presence of the clinical sign of rickets were independently associated with VDD. Clinicians should actively assess for VDD and supplement with vitamin D as indicated, especially among infants < 6 months.</span></span> </p>
文摘Hypophosphatemic vitamin D-resistant rickets or X-linked hypophosphatemia （XLH） is a rare hereditary metabolic disease manifesting marked hypophosphatemia, short stature and rickets. Its prevalence is approximately 1 in 20 000. Except early exfoliation of the teeth, there are a few oral findings of XLH described in China. Here we present two cases in one family.
