Page 53 - Read Online

Page 4 of 11 Malherbe et al. Rare Dis Orphan Drugs J 2024;3:7 https://dx.doi.org/10.20517/rdodj.2023.49

NEWBORN SCREENING IN SOUTH AFRICA
History of biochemical NBS in SA
Biochemical NBS for PKU was investigated in SA in the mid-1960s through a state-funded pilot project
using phenistix testing in Johannesburg (1964-1967), followed by a more comprehensive pilot from
[43]
1979-1981 and a formal programme from 1981-1986 in Pretoria . However, in 1986, the biochemical NBS
programme for PKU and other amino acidopathies was discontinued as it was deemed “neither cost-
effective nor justifiable, especially against the background of other, more pressing health priorities” [43-46] .

A case was made for biochemical NBS of CH in SA in the late 1970s following the global application of
[47]
radio-immunoassay to assess thyroid function . This condition is a prime candidate for biochemical NBS
in SA due to its high birth prevalence (1 in 4,000 or 0.25 per 1,000 live births), the availability of screening
and follow-up diagnostic tests with standard, low-cost (in comparison with many other IEMs)
levothyroxine treatment to prevent disease progression [23,48] . Clinical onset ranges from days, weeks to
months after birth, depending on the cause and extent of thyroid dysfunction, by which time intellectual
[49]
deficits are irreversible regardless of subsequent thyroid replacement therapy . Diagnosis of CH may also
be significantly delayed depending on clinical awareness and experience.

Several biochemical NBS pilot studies for CH were implemented in Pretoria from 1979-1981 (13,146
newborns screened, 2 cases diagnosed clinically) and from 1981-1986 (45,577 newborns screened, 11
diagnosed) [47-49] . A Cape Town pilot project from 1982-1984 screened 28,000 neonates with 6 positive cases
confirmed [48,50] . These pilots indicated that NBS for CH was cost-effective and a “nation-wide unified
screening programme” was recommended . However, without guaranteed adequate follow-up and
[48]
intervention for positive cases, caution was advised, and further investigation was suggested to ensure cost-
effectiveness .
[46]

The first national workshop on CH was held in Cape Town in 1987, with a subsequent meeting in
Johannesburg in 1992 , where CH biochemical NBS data for 1990-1992 from four locations (Cape Town,
[46]
Durban, Johannesburg, and Pretoria) were presented. A total of 65,545 neonates (3.56% of total births) were
[46]
screened, with 12 confirmed CH cases .
As indicated earlier, global advancements improved the sensitivity, reliability, and coverage of biochemical
NBS through tandem MS in the 2000s, leading to an increase in the number of treatable genetic conditions
that could be screened simultaneously . However, in SA, biochemical NBS remained limited. From
[51]
1999-2006, a pilot study funded by the International Atomic Energy Agency (IAEA) screened 42,000
newborns for CH and 13,000 for other IEMs across 12 hospitals in three provinces using tandem MS at
North-West University (NWU) in Potchefstroom . Results from this pilot study and subsequent testing
[52]
indicated that CH, biotinidase deficiency, propionic acidaemia, and galactosemia [due to galactose-1-
phosphate uridyl transferase (GALT) deficiency] are most commonly encountered with biochemical NBS.
Unfortunately, this pilot study did not result in a national biochemical NBS programme , but expertise
[53]
and services at NWU were preserved by offering biochemical NBS to the private healthcare sector on a “fee
for service” basis. Since 2016, a major medical aid scheme in SA has begun to reimburse biochemical NBS
costs, albeit from members’ medical savings accounts. Several other schemes have followed suit. In the
period between January 1998 and September 2023, a total of 125,888 samples (0.5% of all births in SA) were
screened by NWU for 22 conditions, with 80 diagnoses in total, including 16 CH cases [Table 1].

An audit of the CH biochemical NBS programme implemented by the Peninsula Maternal and Neonatal
Service (PMNS) [The PMNS included: Groote Schuur Hospital (GSH), Mowbray Maternity Hospital