POU1F1 mutations in combined pituitary hormone deficiency: differing spectrum of mutations in a Western-Indian cohort and systematic analysis of world literature.

CONTEXT: POU1F1 mutations are prevalent in Indian CPHD cohorts. Genotype-phenotype correlation is not well-studied. AIM: To describe phenotypic and genotypic spectrum of POU1F1 mutations in our CPHD cohort and present systematic review as well as genotype-phenotype analysis of all mutation-positive cases reported in world literature. METHODS: Retrospective study of POU1F1 mutation-positive patients from a western-Indian center. PRISMA guidelines based pubmed search of published literature of all mutation-positive patients. RESULTS: Our cohort had 15 POU1F1 mutation-positive patients (9 index, 6 relatives). All had severe GH, TSH and prolactin deficiencies (GHD, TSHD and PD). TSHD was diagnosed earliest followed by GHD (median ages: TSHD-6 months, GHD-3 years), while PD was more variable. Two sisters had central precocious puberty at 7 years of age. Pubic hair was deficient in all post-pubertal patients (females: P1-P2, males: P3-P4). Splice-site/intronic/frameshift mutations were most common, while missense/nonsense mutations were less frequent (33%). Review of world literature yielded 114 patients (82 index patients) from 58 studies. GHD was present in all patients. TSHD was spared in 12.5% and PD in 4.4% patients. Missense/nonsense mutations accounted for 75% of spectrum. Phenotype-genotype analysis revealed higher mean peak-GH levels (1.1 vs 0.2 ng/ml, p = 0.008) and lower prevalence of anterior-pituitary hypoplasia (63.6% vs 86.3%, p = 0.03) in patients with heterozygous than homozygous and compound heterozygous mutations. CONCLUSIONS: We present largest series of POU1F1 mutation-positive patients. Precocious puberty and defective pubarche are lesser-appreciated phenotypic features. Our mutation spectrum is different from that of world literature. Patients with heterozygous mutations have milder phenotype.

Genetic spectrum and predictors of mutations in four known genes in Asian Indian patients with growth hormone deficiency and orthotopic posterior pituitary: an emphasis on regional genetic diversity.

CONTEXT: Regional variation in prevalence of genetic mutations in growth hormone deficiency (GHD) is known. AIM: Study phenotype and prevalence of mutations in GH1, GHRHR, POU1F1, PROP1 genes in GHD cohort. METHODS: One hundred and two patients {Isolated GHD (IGHD): 79; combined pituitary hormone deficiency (CPHD): 23} with orthotopic posterior pituitary were included. Auxologic, hormonal and radiological details were studied. All four genes were analysed in IGHD patients. POU1F1 and PROP1 were studied in CPHD patients. RESULTS: Of 102, 19.6% were familial cases. Height SDS, mean (SD) was - 5.14 (1.63). Peak GH, median (range) was 0.47 ng/ml (0-6.59), 72.5% patients had anterior pituitary hypoplasia (APH). Twenty mutations (novel: 11) were found in 43.1% patients (n = 44, IGHD-36, CPHD-8). GHRHR mutations (n = 32, p.Glu72* = 24) were more common than GH1 mutations (n = 4) in IGHD cohort. POU1F1 mutations (n = 6) were more common than PROP1 mutations (n = 2) in CPHD cohort. With few exceptions, this prevalence pattern is contrary to most studies in world-literature. No patients with peak GH > 4 ng/ml had mutations, signifying it as negative predictor. While many parameters were significant on univariate analysis, only positive family history and lower median peak GH levels were significant predictors of mutations on multivariate analysis in IGHD patients. CONCLUSION: At variance with world literature, we found reverse predominance of GHRHR over GH1 mutations, POU1F1 over PROP1 mutations and predominance of GHRHR p.Glu72* mutations thus re-affirming the regional diversity in GHD genetics. We report positive and negative predictors of mutations in GHD.