A Study of the Effects of Fabrazyme (Agalsidase Beta) on Mother's Lactation and on the Growth, Development and Immunologic Response of Their Infants

• Presence of alpha-galactosidase (αGAL) activity in breast milk of mothers who are being treated with Fabrazyme (agalsidase beta) during lactation [ Time Frame: Time frame: Month 1, 3, and 6] ] [ Designated as safety issue: No ]
• Growth and development of infants born to mothers who have received Fabrazyme (agalsidase beta) treatment during lactation [ Time Frame: Up to 24 months ] [ Designated as safety issue: No ]
• Volume, total fat and protein content in breast milk of mothers who are being treated with Fabrazyme (agalsidase beta) during lactation [ Time Frame: Month 1, 3, and 6 ] [ Designated as safety issue: No ]
• Pharmacokinetics: Milk αGAL to plasma αGAL ratio [ Time Frame: Months 1, 3, and 6 ] [ Designated as safety issue: No ]
• Formation or continued presence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to α-galactosidase A (r-hαGAL) in infants receiving breast milk from mothers treated with Fabrazyme (agalsidase beta) during lactation [ Time Frame: Baseline, Months 2, 6, and 12 ] [ Designated as safety issue: Yes ]

• Observe the effect of Fabrazyme on lactation.
• Is a-galactosidase A is present in the breast milk of mothers with Fabry.
• Determine affects on growth, development, and immunologic response of infants born to mothers with Fabry disease being treated or who have received treatment during their pregnancy with Fabrazyme.

The purpose of this study is to observe the potential effects of Fabrazyme (agalsidase beta) treatment on lactation and on the growth, development, and immunologic response of infants born to mothers with Fabry disease who are treated with Fabrazyme during lactation. There are 3 participation scenarios: mother/infant full participation, mother full participation/infant development assessment only, and mother full participation/infant no participation. Whether or not the mother continues to lactate will be assessed at each visit. If the mother is no longer lactating, the mother will discontinue this study but continue to be followed in the Fabry Registry. The infant (if participating) will be followed for development only for the remainder of this 24 month study.

NOTE: Estimated Enrollment: 10 mothers and up to 10 infants

• Experimental: Mother and Infant all assessments
  Note: A participating mother may choose the level of participation for her infant (i.e., these arms are not assigned randomly)
  Intervention: Biological: agalsidase beta
• Experimental: Mother all assessments, Infant developmental assessments only
  Note: A participating mother may choose the level of participation for her infant (i.e., these arms are not assigned randomly)
  Intervention: Biological: agalsidase beta
• Experimental: Mother only/ no infant
  Note: A participating mother may choose the level of participation for her infant (i.e., these arms are not assigned randomly)
  Intervention: Biological: agalsidase beta

Inclusion Criteria:

• Mother must provide signed written informed consent to participate in this study.
• Mother must be enrolled in the Fabry Registry and receiving Fabrazyme (agalsidase beta) while lactating.
• Mother must agree to adhere to the Fabry Registry recommended schedule of assessments for medical history, pregnancy outcome, genotyping, and antibody testing.
• Mother must agree to adhere to the schedule of evaluations for this study.
• Infant must have the signed written informed consent of the parent(s)/legal guardian(s) to participate in this study.
• Infant must be born to a mother who is receiving Fabrazyme (agalsidase beta) during lactation.
• Infant must be receiving breast milk from the mother.
• Infant must have the agreement of the parent(s)/legal guardian(s) to adhere to the schedule of evaluations for this study.

Exclusion Criteria:

• The mother and infant will be excluded from this study if the mother has received an investigational drug within 30 days prior to study enrollment.