Congenital pulmonary airway malformation associated with mosaic Klinefelter syndrome.

A 26-year-old female, G4 P2012 presented for an anatomy scan at 18 weeks. Multiple macrocysts were seen in the left fetal lung, which lead to a diagnosis of congenital pulmonary airway malformation (CPAM) type II. A fetal MRI examination performed at 24 weeks of gestation confirmed the diagnosis of CPAM type II. A genetic amniocentesis was done to rule out a fetal chromosomal abnormality and the fetus was found to have mosaic Klinefelter syndrome. Fetal CPAM is not usually associated with chromosomal abnormalities unless there are other fetal malformations present. This is the first known case where a fetus with CPAM and no other malformation was found to have mosaic Klinefelter syndrome. Therefore, we believe it is prudent to offer prenatal diagnostic testing whenever a fetus with CPAM is identified with ultrasound.

Prenatal ultrasound diagnosis of a 48,XXYY syndrome.

The 48,XXYY syndrome is a rare uncommon gonosome aneuploidy and its incidence is estimated to be 1:18,000-1:40,000. The phenotype associated with this syndrome, classically described as Klinefelter variant, is extremely variable but developmental abnormalities are always present. Ultrasound signs during pregnancy are inconsistent, and only three prenatal cases have been described in the literature. Here, we report a case of 48,XXYY syndrome identified in prenatal period because of the presence of polyhydramnios and bilateral clubfeet on second trimester ultrasound. This observation shows the importance of chromosomal prenatal diagnosis in cases with bilateral clubfeet on morphologic ultrasound. This diagnosis is essential for further characterization of the prenatal phenotype and to improving genetic counselling.

Are Klinefelter boys hypogonadal?

UNLABELLED: Male hypogonadism implies decreased function of one or more testicular cell population, i.e. germ, Leydig and/or Sertoli cells. In the normal prepubertal boy, Sertoli cells are very active, as indicated by high anti-Müllerian hormone (AMH) and inhibin B secretion, whereas the functional activity of Leydig cells is minimal, as evidenced by low testosterone production, and germ cells do not undergo the full spermatogenic process. Klinefelter syndrome is the most frequent cause of hypogonadism in the adult male. In this review, we discuss whether the gonadal failure is already established during infancy and childhood. In Klinefelter syndrome, there is increased germ cells degeneration from mid-foetal life - resulting in a decreased number at birth - which persists during infancy and childhood and becomes dramatic during puberty. Controversial results exist in the literature regarding Leydig cell function in Klinefelter boys: while some authors have found normal to low testosterone levels in infancy and childhood, others have reported normal to high values. Sertoli cell products AMH and inhibin B are normal in prepubertal boys and only decline during mid- to late puberty. CONCLUSION: Klinefelter syndrome is a primary hypogonadism affecting all testicular cell populations. Germ cells are affected from foetal life, and a severe depletion occurs at puberty. Leydig cell function may be normal or mildly affected in foetal and early postnatal life. Sertoli cell function is not impaired until mid- to late puberty, as reflected by normal AMH and inhibin B in Klinefelter boys.

Inhibin B and anti-Müllerian hormone, but not testosterone levels, are normal in infants with nonmosaic Klinefelter syndrome.

Klinefelter syndrome is a major cause of infertility in the male. Nevertheless, pregnancies were recently obtained by intracytoplasmic injection of sperm retrieved by surgery or ejaculation, underscoring the need to understand the role of Sertoli and Leydig cell secretions during development. In 18 infants with prenatally diagnosed homogenous 47,XXY karyotype, blood samples were taken from birth to 3 yr of age. Inhibin B (INHB), anti-Müllerian hormone (AMH), testosterone, FSH, and LH levels were compared with those in six adolescents with XXY karyotype and reference values established in 215 control infants. In XXY infants FSH, LH, INHB, and AMH did not differ from controls. Testosterone levels during the first trimester exhibited a physiological increase but were lower than in controls (P = 0.0001). Significant correlations were found between testosterone and LH (P < 0001), between INHB and FSH (P = 0.0011), and between AMH and INHB (P = 0.025). In XXY adolescents, AMH and INHB were undetectable. Our findings demonstrate that testosterone secretion is impaired in infants with Klinefelter syndrome. By contrast, INHB and AMH secretions were not altered, which raises the question of the mechanism(s) governing the decline of Sertoli cell function after puberty.

Sexual development, normal and abnormal.

An understanding of normal sexual development is essential to understanding abnormal sexual development. Normal differentiation of the bipotential external genitalia, reproductive ducts, and gonads are dependent upon the presence or absence of androgens from any source, the presence or absence of mullerian inhibiting factor from the fetal testes, and the number and type of sex chromosomes present respectively. Abnormal differentiation results from an imbalance of one or more of these factors or peripheral resistance to these factors.