Predictors of Risk for Abnormal Karyotype in Dysmorphic Children

Abstract

BACKGROUND Chromosomal anomalies occur in 0.4% of live births. The phenotypic anomalies that result from chromosomal aberrations have multiple minor face-and limb-anomalies. These assume diagnostic significance in combination. Major congenital defects can be defined, rather arbitrarily, as those abnormalities that if uncorrected, impair normal body function or reduce life expectancy. Most babies with two major anomalies or one major and two minor anomalies or three or more minor anomalies have a dysmorphic syndrome. This study aimed at analysing the clinical and karyotypic profile of a section of dysmorphic children presenting in a tertiary care centre and to correlate the dysmorphology with the results of karyotyping. The aim of the study is to assess the clinical and karyotypic profile of a group of children with congenital anomalies and dysmorphic facies attending OPD and IP of the Department of Paediatrics, SATH, TVM Medical College. MATERIALS AND METHODS Children who were enrolled were evaluated using a detailed proforma to analyse the clinical profile. Then 2-4 ml venous blood was collected in sodium heparinised vacutainer with aseptic precautions and sent for karyotyping. 53 children referred with multiple anomalies, failure to thrive, dysmorphic facies, abnormal dermatoglyphics and other major and minor anomalies were included in the study. RESULTS Of the 53 dysmorphic children screened, 73.58% had abnormal karyotype. This included numerical autosomal anomalies (50.9%), numerical sex chromosomal anomalies (3.77%), structural autosomal chromosomal anomalies (7.54%) or structural sex chromosomal anomalies (3.77%). There were 3 cases of Fanconi's anaemia and a case of fragile X syndrome in the sample. CONCLUSION Among the 53 children, 73.58% had an abnormal karyotype. Those with two major anomalies or one major and two minor anomalies or three minor anomalies were included in the study. One major anomaly may not be indicative of a chromosomal anomaly whereas association of various major and minor anomalies may indicate a chromosomal defect. As karyotyping and further studies to detect chromosomal anomalies are expensive, selection of cases was based on inclusion criteria yields a high positivity rate.

The simian crease: Relationship to various genetic disorders

“…Simian creases are not exclusively characteristic of EDs; however, syndromes where simian creases have also been documented, sporadically or in high incidence, will be discussed in detail or catalogued (Table ). It is also worth remarking that karyotypically normal children can also carry the simian crease, the incidence being reported at approximately 7.6% in one study (Ravi et al, ). Overall, simian creases are badly misunderstood from the genetic standpoint.…”