Prader-willi Syndrome (pws) By Methylation Specific Pcr (ms-pcr), The Establishment Of The Diagnosis And Clinical Manifestations Of Endocrine Disorders Discussed

Objectives:Prader-Willi syndrome (PWS) is a complex, multisystem disorder, caused byabsence of expression of the paternally active genes in the PWS critical region on15q11-13. Its major clinical features include neonatal hypotonia, developmental delay,short stature, behavioral abnormalities, childhood onset obesity, hypothalamichypogonadism, and characteristic facial features with dolichocephaly in infancy,narrow face or bifrontal diameter, almond-shaped eyes, smallappearing mouth withthin upper lip, down-turned corners of the mouth. There are three major geneticabnormalities, including paternal deletion of the 15q11-q13 region, maternaluniparental disomy (UPD), and imprinting center (IC) mutations. Methylation-specific PCR method (MSPCR) having high sensitivity and specialty, is a fast andefficient method to diagnose PWS. The purpose of our study is to establish steadyMSPCR method to diagnose PWS, then evaluate the growth, biochemistry situation,and endocrine situation for the patients primarily.Methods:1. Blood samples were taken frome the 6 patients who have been diagnosedas PWS according to PWS clinical diagnostic criteria. DNA was extracted by a saltout method, and then was treated using CpGemone^TM Fast Modification kit formodification by sodium bisulfite. After the modification, specific PCR performed andthen the product was separated on a 4% agarose gel. We use the DNA from normalpeople as a control.2. The height, weight, biochemistry indexes, the OGTT test, the serumlevels of hormone (including growth hormone, sex hormone, adrenocortical hormone,thyroid hormone) were examined in five patients who were confirmed by MSPCRmethod. The same indeces from the normal age-matched people were as a control.Results:1. All of the six patients, including 3 males and 3 females, aged 1.9 to 17years, presented hypotonia and feeding problems in neonatal period, hyperphagia andexcessive weight gain at 1 to 5 years old. Three patients manifested hypogonadism. Two DNA fragment bands (174bp and 100bp) were detected that were respectivelyfrom maternal and paternal in normal people, and only single band (174bp, frommaternal) was detected in the patient with PWS. The result was consistent completelywith the clinical diagnosis.2. The results of primary evaluation for the 5 patients (including 3 males and2 females, aged 2 to 19 years) in the growth, biochemistry situation, endocrinesituation showed as following: obesity in 5 patients (BMI 29.24±9.30kg/m²); shortstature in 2 patients (lower than age-matched people two SD); increased level oftriglyceride (TG) in 2 patients (2.35～3.54mmol/L); increased level of ApoB in 1patient (1.1 g/l); increased level of hs-CRP in 4 patients (4.21～＞10mg/L). Only 1patient showed the abnormal of liver function (ALT 126U/L). The kidney functionwas normal in all of the 5 patients. The level ofhs-CRP,CHO,LDL-C,ApoB,ALT in PWS patients were different from normal age-matched people (P＜0.05). Thegrowth hormone stimulation test was performed in 4 patients, and all the resultsshowed growth hormone deficiency (GHmax 2.974±2.966ng/ml). The sex hormonewas detected in 3 patients and the serum levele of testosterone in an adult patient wasdecreased (1.7nmol/L). The level of the urine free cortisol was detected in 4 patientsand all the results were normal (18.003±3.3273ug/24h). The level of thyroidhormone was detected in 4 patients and only one of the results was mild abnormal(TSH 5.591 uIU/ml, TT3 2.23ng/ml). The level of the urine free cortisol and thyroidhormone had no difference with normal age-matched people (P＞0.05). The OGTTtest was performed in 4 patients, in which two patients were diagnosed as diabetesmellitus, one patient was diagnosed as IGT.Conclusions:1. MSPCR method is a fast and efficient method with a good sensitivityand specialty for diagnosing suspicious PWS patient. The method could be appliedextensibly for clinical diagnosis.2. Obesity and short stature, growth hormone deficiency and the sex hormonelevel abnormal were detected in PWS patients. The patients with predisposed todiabetes mellitus or Impaired glucose tolerance (IGT).