Placenta may be utilized for the diagnosis of cystinosis in the newborn. The whole placenta is shipped on wet ice. Fetal tissue is sampled and assayed for intracellular cystine. The values in a cystinosis fetus are more than ten-fold greater than normal. Carriers cannot be reliably diagnosed.

For 13 normal control placentas:

0.16 ± 0.06 nmol 1/2 cystine/mg protein (0.07-0.29)    [mean ± S.D. (range)]

For 8 at risk placentas with follow-up confirmation that infant does not have cystinosis

0.24 ± 0.15 nmol 1/2 cystine/mg protein (0.09-0.56)

For 6 cystinotic placentas:

4.8, 2.9, 70, 2.3, 4.2, 2.0 nmol 1/2 cystine/mg protein

Placenta for newborn diagnosis of cystinosis
Contact the Cystine Determination Lab to request information of preparation of the sample and to schedule personnel to receive it. The entire placenta is shipped to the Cystine Determination Lab on wet ice. (DO NOT use dry ice.)