A novel germline mutation, IVS4+1G>A, of the POU1F1 gene underlying combined pituitary hormone deficiency.
BACKGROUND
POU1F1 is a pituitary transcription factor that plays a pivotal role in pituitary development and expression of the GH, PRL and TSH beta genes. Therefore, abnormalities of the POU1F1 gene are known to be responsible for a phenotype causing combined pituitary hormone deficiency (CPHD) involving growth hormone, prolactin and thyrotropin.


METHODS
We described an 18-year-old Thai man, from a consanguineous family, who presented with short stature and cognitive deficit. He underwent endocrinological and molecular investigations.


RESULTS
Hormonal studies showed that the patient had GH deficiency and secondary hypothyroidism, consistent with CPHD. Direct DNA sequencing revealed a novel homozygous mutation at the splice site of exon 4, IVS4+1G>A. It is the first splice site mutation in the POU1F1 gene described to date. Of the 7 other family members studied for this mutation by restriction enzyme digestions, 5 were heterozygous. They were all unaffected, suggesting a recessive pattern of inheritance.


CONCLUSIONS
We described a novel POU1F1 splice site mutation, IVS4+1G>A, the first of its kind, in a Thai patient with CPHD. Recessive inheritance is suggested. We also noted preventable morbidities which resulted from delay in diagnosis of concomitant pituitary hormone defects in newborns suspected of CPHD.
Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Thiti.s@chula.ac.th
Thiti
T
Snabboon
Wanee
W
Plengpanich
Patinat
P
Buranasupkajorn
Ratchada
R
Khwanjaipanich
Padiporn
P
Vasinanukorn
Sompongse
S
Suwanwalaikorn
Weerapan
W
Khovidhunkit
Vorasuk
V
Shotelersuk
D000293:Adolescent; D005192:Family Health; D005260:Female; D018095:Germ-Line Mutation; D006720:Homozygote; D006801:Humans; D007018:Hypopituitarism / Q000235:genetics* / Q000473:pathology; D007037:Hypothyroidism / Q000235:genetics; D008279:Magnetic Resonance Imaging; D008297:Male; D010375:Pedigree; D010907:Pituitary Hormones / Q000172:deficiency*; D012150:Polymorphism, Restriction Fragment Length; D050817:Transcription Factor Pit-1 / Q000235:genetics*
C494187:POU1F1 protein, human; D010907:Pituitary Hormones; D050817:Transcription Factor Pit-1