Fernanda Salles Reis1
Débora Cristiane Gomes2
Henrique Pierotti Arantes3
Marise Lazaretti-Castro1
1 Departamento de Medicina,
Disciplina de Endocrinologia,
Universidade Federal de São Paulo
(Unifesp), São Paulo, SP, Brasil
2 Departamento de Medicina,
Serviço de Endocrinologia
Pediátrica, Universidade
Federal de Uberlândia,
Minas Gerais, MG, Brasil
3 Instituto Master de Ensino
Presidente Antônio Carlos
(IMEPAC), Araguari, MG, Brasil
Hypophosphatasia (HPP) is a rare disease with a high mortality rate in its severe forms. It is caused
by mutations within the gene encoding the tissue-nonspecific alkaline phosphatase (TNSALP), an
enzyme responsible for bone mineralization. In 2015, the Food and Drug Administration approved
the use of asfotase alfa, the first medication showing benefit in the treatment of HPP. We describe
a case with a 2-year follow-up of the first Brazilian child treated with asfotase alfa. A 5-year-old
boy, born to consanguineous parents, was diagnosed with HPP at the age of 20 months. During
prenatal ultrasonography, polyhydramnios and shortening of long bones were detected. After birth,
he presented delayed motor development, repeated respiratory infections, and bone deformities.
At the age of 2 years and 8 months, he started walking and had already lost his primary teeth. He
had reduced levels of alkaline phosphatase (ALP), elevated levels of pyridoxal 5’-phosphate (PLP),
and a p.Ala33Val (c.98C>T) missense mutation in homozygosis in the TNSALP gene. His parents
and sister also had reduced ALP levels, high PLP levels, and the same mutation in heterozygosis.
His father and sister were healthy, and his mother was diagnosed with rickets in childhood, which
resulted in short physical stature and lower limb deformities. The patient was started on asfotase alfa
at the age of 2 years and 10 months. After 2 years of treatment, he improved his motor skills, had
no further episodes of severe respiratory infection, and showed improved radiological findings of
rickets, without any severe side effect.
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