The distinctive clinical finding of the subject was bilateral, typical, complete coloboma of iris extending up to the ciliary border. This has not been previously reported in cases with the 48,XXXX constitution. Individuals with 48,XXXX have been described as pleasant, friendly, cooperative, aggressive and emotionally labile [4]. Our patient was shy with an IQ of 43. Mental retardation is characteristic of 48,XXXX with an average IQ of 60 (range 30-70). Major psychological/psychiatric studies [5] suggest that schizophrenic symptoms may be more frequent in subjects with tetrasomy X, than in the general population. The phenotype in tetrasomy X is very heterogeneous, the presence of extra sex chromosomes having a detrimental effect on growth, development and the general phenotype. Most often the skeletal, cardiac and gonadal systems are affected, with a varying degree of facial dysmorphism and speech impairment [4]. Cammarata et al. [6] reported midface hypoplasia, hypertelorism, upslanting palpebral fissures, epicanthal folds, low nasal bridge, micrognathia, short neck, clinodactyly of fifth finger and metaphyseal enlargement of long bones in 48,XXXX patients. Most of these features were present in our patient. Linden et al. [4] described a patient with facial asymmetry, delayed development and poor motor coordination.

The loss of an X chromosome results in short stature and often in primary ovarian failure [7], whereas an extra X chromosome is responsible for increased height. Tall stature is common in tetrasomy X females, with an average height of 169 cm [4]. Our patient was 162.8 cm (average height 156 cm, for Indian females of 16+ years) [8] and had normal menarche. Three 48,XXXX women have given birth to children with a normal karyotype, with trisomy and with omphalocele, respectively [9]. Half of the cases with 48,XXXX have normal menarche and menopause, while the rest have menstrual dysfunction [9-11].

The errors in meiosis I influence the likelihood of error in meiosis II and in early mitotic division. In most if not all cases, chromosome tetrasomy is attributed to successive non disjunctional events involving the same parent [12]. In most cases, additional chromosomes are derived from one parent and the other parent contributes a single X or Y chromosome.

This 48,XXXX syndrome can be diagnosed best by karyotyping, and most cases are ascertained because of clinical findings. Fluorescent in situ hybridization is used successfully to detect aneuploidies and to confirm the results of chromosomal analyses. The reporting of more cases can elucidate the clinical phenotype in females with tetrasomy X. Furthermore, molecular studies in such cases should reveal the effect of an extra X chromosome on growth and facial dysmorphism.