Further case of trisomy 18 mosaicism with a mild phenotype

✍ Scribed by Collins, A. L. ;Fisher, J. ;Crolla, J. A. ;Cockwell, A. E.

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 185 KB
• Volume: 56
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320560129

✦ Synopsis

this journal published a case report of trisomy 18 mosaicism in a 13-year-old girl with normal intelligence, delayed pubertal development, and growth failure [Sarigol and Rogers, 19941. We now report a further case of trisomy 18 mosaicism with a mild phenotype, this time presenting with congenital alopecia and premature ovarian failure.

The patient was the third child of healthy nonconsanguinous Caucasian parents. She was born at term after a normal pregnancy, birthweight 3.27 kg. There were no problems in the neonatal period, but a total absence of scalp hair was noted. She has had recurrent middle ear infections since then, without residual hearing loss. She developed only a few scalp hairs in childhood, and wore a wig from age 3 years. She walked at 20 months (as did her two normal brothers), and general development was at the slow end of the normal range. She attended normal schools until the age of 17, and achieved some low grade passes in examinations. She is now employed training others in factory work, and lives independently.

She first menstruated at age 13 years, followed by 4 menses at 6-month intervals, and then amenorrhoea. At 22 she was referred to an endocrinology clinic, and karyotyping was performed to exclude Ullrich-Turner syndrome. At this time she also complained of bone aches.

On examination she did not have an obviously abnormal appearance (Fig. 1). She had a normal build, height of 162.5 cm (50th centile), and OFC of 54.4 cm (50th centile). She had sparse eyebrows, eyelashes, and axillary and pubic hair. Her skin was very soft and smooth, and fingertip dermatoglyphics could not be determined. There was thinning of the upper helix of both ears. Breast development was normal, although the nipples were rather flat. On the scalp she had sparse, coarse black hairs (Fig. 2). She still wears a wig.