人类遗传学与胚胎学

Mucopolysaccharidosis (MPS) is a group of autosomal recessive metabolic disorders caused by the absence or malfunctioning of the lysosomal enzymes needed to break down molecules called glycosaminoglycans (GAGs). All the MPSs are inherited in an autosomal recessive fashion except Hunter syndrome (MPS type II), which is X-linked. Common clinical presentation includes facial dysmorphism, hepatosplenomegaly, joint stiffness and contractures, pulmonary dysfuction, myocardial enlargement and valvular dysfunction and neurological involvement. We report 17 yr old boy with features suggestive of Hunter syndrome associated with ventricular septal defect.

Abstract
Objective: The objective of the study is to report the association between the phenotype of the Turner syndrome with that of its karyotype and the parental origin of the X. 181 female referred to division of human genetics, St. John’s Medical College with different referral reasons are included in 1st phase of the study to observe the karyotype, upon obtaining the consent. Families of probands with confirmed pure or mosaic (more than 10% of mosaic status) karyotype of Turner stigmata are requested to participate in 2nd phase of study to determine the parent of origin. 20 families agreed and gave the consent for the study.
Material and Method: The Karyotype analsyis was carried by GTG banding method automated karyotyping system. The parental origin was determined by X chromosome specific short tandem repeat (STR) markers. 23 Turner stigmata features were listed in the proforma. The secondary measure is to observe the associated Turner stigmata with the determined karyotype and the parental origin.
Results: In 11 female probands, one had X structural abnormality (45,X/46,X,i(Xq)); 2 had X-mosaicism (45,X/ 46,XX) and 8 had 45,X. The determined parental origin of X was maternal in 8 (72.7%) and paternal in 3 (27.2%).
23 phenotypic features of Turner stigmata were tabulated. The features were further categorized as general observations, classical features of TS, features based on ultrasound findings and behavior. Percentage analysis indicated that a higher concordance of phenotype and behavior in proband with maternal X.
Conclusion: In the present study, the Turner syndrome features were seemed to be associated with the maternal origin of X in Turner syndrome.