MM9 was 13 years of age at the time of investigation, had moderate mental retardation (IQ-43), and was attending the Red Cross School for Mentally Challenged at Amritsar, India. A detailed pedigree analysis and evaluation of the clinical findings was undertaken. She was a full-term first-born of a 17-year-old mother and a 23-year-old father. She had a high forehead, flat nasal bridge, small ears, hypertelorism, divergent strabismus, bilateral, typical, complete coloboma of iris (6 o’clock position), extending up to the ciliary border, long philtrum, short neck, short fifth finger and a height of 162.8 cm (Figure 1). The skull radiograph was suggestive of intracranial tension and bitemporal narrowing. The X-ray report did not indicate radioulnar synostosis, while elbow and wrist radiographs suggested her bone age to be 12 to 14 years. Her teeth were irregular and placed in two rows with gingival hyperplasia (Figure 2). Ultrasonography of the abdomen showed normal results. Her uterus measured 6.5 ´ 2.5 cm. The ovaries were of normal size and she had a normal menstrual history. The serum levels of IgM, IgG and IgA were within normal limits. She showed delay in comprehensive and expressive speech. Her karyotype showed a non mosaic, chromosomal constitution of 48,XXXX (Figure 3). The karyotypes of her parents and her younger brother showed normal chromosomal constitution. For the fluorescent in situ hybridization (FISH) analysis, 500 interphase lymphocyte nuclei were scanned, and four signals were seen with the CEP-X probe (Figure 4). Her father had a history of head injury and subsequent seizures. He had been taking phenytoin at the time of her conception.

Cytogenetic and Molecular Analysis. Chromosomal preparations were made from phytohemagglutinin-stimulated peripheral lymphocytes using RPMI1640 medium and standard culturing technique with modifications [3]. Chromosomal analyses were performed on all four family members. Chromosomal banding was done by Trypsin-Giemsa GTG banding. Consent was obtained from the parents before investigations began. From the patient, 100 metaphases were examined for numerical and structural chromosomal abnormalities and karyotyped, 500 interphase nuclei were scored for FISH which was performed with a CEP-X probe (spectrum orange) according to the manufacturer’s instructions (Vysis UK Ltd., now part of Abbott Molecular, Des Plaines, IL, USA). After hybridization, a rapid wash procedure was followed. Chromosomes were counter stained with 4'-6-diamidino-2-phenylindole (DAPI) and viewed by using triple band-pass filter and Quips Smart Capture Imaging Software (Vysis UK Ltd.).