20 DISCOVERMAGAZINE.COMKELLIEJA
EG
ER
/DISC
OVERHaving
an XY
genotype
explained
why
Ameera’s
left ovary
was barely
formed.
It also
explained
why she
had no
uterus.was a gonadoblastoma,
a type of tumor that was
not cancerous, but could
eventually become so. We
made plans to remove it in
a subsequent surgery.
Such tumors are found
in a few known diseases,
such as Swyer syndrome,
in which patients have
neither ovaries nor
testes, or Denys-Drash
syndrome, which usually
includes a specific type
of kidney tumor called
a Wilms tumor. She had
neither of these. One
other syndrome seemed
quite possible, but deter-
mining whether she had it
meant learning a bit more
about Ameera.
So, after her surgery, we drew blood for
further testing. All we could do now was
wait, and hope this would finally reveal
what caused her illness.FINALLY, AN EXPLANATION
After an anxious week, we finally
received the test results: an XY genotype.
According to her chromosomes, Ameera
was male.
Most humans have 23 sets of chromo-
somes, which contain genes that dictate
how we develop, our appearance and
many other features. One set of chro-
mosomes determines biologic sex: XX
for female or XY for male. All human
embryos effectively begin as females, the
default pathway for development. But
early on, the presence of a Y chromosome
halts formation of female reproductive
organs such as the ovaries and uterus.
These embryos usually develop testes and
male genitalia instead — unless some-
thing occurs to stop it.
Having an XY genotype explained why
Ameera’s left ovary was barely formed.
It also explained why she had no uterus.
And yet, her body did not produce
enough male hormone to allow for for-
mation of a male reproductive system.
It’s unclear what caused this disruption,VITAL SIGNS
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