Familial Turner syndrome with an X;Y translocation mosaicism: implications for genetic counseling.
Spontaneous fertility is rare among patients with Turner syndrome and is most likely in women with mosaicism for a normal 46,XX cell line. We report an unusual case of familial Turner syndrome with mosaicism for a novel X;Y translocation involving Xp and Yp. The chromosomal analysis was carried out through cytogenetics and molecular karyotyping using a SNP array platform. The mother, a Turner syndrome woman, diagnosed in midchildhood because of short stature, was found to have a 45,X/46,X,der(X)t(X;Y)(p11.4;p11.2) karyotype, with a predominant 45,X cell line. Her parents decided against prophylactic gonadectomy, generally recommended at an early age when Y chromosome has been identified, because at age 13, she had spontaneous puberty and menarche. She reached a final height of 154 cm after treatment with growth hormone. At age 24, she became spontaneously pregnant. She had a mild aortic coarctation and close follow-up cardiac evaluation, including cardiac magnetic resonance imaging, had been performed during her pregnancy, which progressed uneventfully, except for intra-uterine growth retardation. Prenatal diagnosis revealed a female karyotype, with transmission of the maternal translocation with an unexpected different mosaic:47,X,der(X)t(X;Y)x2/46,X,der(X)t(X;Y) karyotype. This complex and unusual karyotype, including a mosaic partial trisomy X and a non-mosaic Xpter-Xp11.4 monosomy, results in transmission of Turner syndrome from mother to daughter. At birth, the girl had normal physical examination except for growth retardation. This family illustrates the complexity and difficulties, in term of patient counseling and management in Turner syndrome, in determining ovarian status, fertility planning, risks associated with pregnancies, particularly when mosaicism for Y material chromosome is identified.
Service de Génétique et Embryologie médicales, Hôpital Armand Trousseau, APHP, UPMC, France. marie-france.portnoi@trs.aphp.fr
Marie-France
MF
Portnoï
Sandra
S
Chantot-Bastaraud
Sophie
S
Christin-Maitre
Bruno
B
Carbonne
Marie-Paule
MP
Beaujard
Boris
B
Keren
Jonathan
J
Lévy
Marc
M
Dommergues
Sylvie
S
Cabrol
Capucine
C
Hyon
Jean-Pierre
JP
Siffroi
D000328:Adult; D041321:Chromosomes, Human, X / Q000235:genetics*; D041322:Chromosomes, Human, Y / Q000235:genetics*; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D007231:Infant, Newborn; D009030:Mosaicism; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D014178:Translocation, Genetic; D014424:Turner Syndrome / Q000175:diagnosis / Q000235:genetics*