Is it possible that my husband's small penis is hereditary?

Everyone hopes that their married life will be happy and fulfilling. It is necessary for couples to have a normal sex life after marriage. However, some women may find that their husband's penis is small, and it may affect their husband's sexual desire. The more serious thing is that they may worry about the possibility of genetic disease.

Pathological etiology

The causes of micropenis include: ① hypogonadism due to insufficient secretion of gonadotropin; ② hypogonadism due to excessive secretion of gonadotropin; ③ primary micropenis.

1. Hypogonadism due to insufficient secretion of gonadotropin

(1) Abnormal brain tissue structure: Children with anencephaly have no hypothalamic secretion function. Even if the pituitary gland develops normally, the lack of gonadotropin-releasing hormone leads to low testosterone secretion, resulting in micropenis. Congenital pituitary agenesis, hypothalamic dysfunction caused by partial corpus callosum dysplasia, occipital encephalocele with movement disorder and other midline brain development abnormalities all cause micropenis due to insufficient gonadotropin secretion. In addition, it also leads to multiple malformations of other systems.

(2) Congenital gonadotropin-releasing hormone deficiency without brain tissue abnormality: Micropenis caused by this type of reason is more common than the previous one. The specific cause is unclear. Most of them are various syndromes, such as Kallmann syndrome, Prader-Willi syndrome, Lawrence-Moon-Beidel syndrome, etc., often accompanied by multiple malformations. According to research, it is related to chromosome and gene abnormalities. There are also deficiencies of gonadotropin-releasing hormone and luteinizing hormone caused by endocrine and biochemical metabolic abnormalities.

2. Hypogonadism due to excessive secretion of gonadotropin. The secretion functions of the hypothalamus and pituitary gland of this type of patient are normal, but the testicles undergo degeneration in the late pregnancy, resulting in a decrease in testosterone secretion, which leads to excessive secretion of gonadotropin through negative feedback. The main cause of micropenis lies in the testicles themselves, such as congenital absence of testicles and incomplete testicular descent. Some patients have normal testicles, but their luteinizing hormone receptors are abnormal, so they cannot secrete enough testosterone. In addition, attention should be paid to whether there is any gender abnormality.

3. Primary micropenis In addition to the above reasons, a small number of patients have normal secretion of hormones in the hypothalamus-pituitary-testis axis, but have micropenis deformities, which grow again during puberty. The cause is unclear, but it is speculated that it may be due to delayed stimulation of gonadotropin in the late embryonic period, transient decrease in testosterone secretion, etc. A small number of patients may also have androgen receptor abnormalities.

Patients with micropenis may have sex chromosome abnormalities, such as Klinefelter syndrome (47,XXY), poly-X syndrome (48,XXXY and 49,XXXXY), and polychromosomal abnormalities (69,XXY triploidy).

Disease Diagnosis

1. Hidden penis The penis is not fully developed and is hidden under the skin, like a small penis. However, the patient is obese and has thick subcutaneous fat, so the penis is buried in the subcutaneous fat tissue of the foreskin and pubic area.

2. Scrotal edema: The scrotum is excessively swollen and the penis is buried in it. However, there is a history of filariasis infection, and the scrotal skin is thickened, rough and cracked, sometimes involving the skin of the thighs and lower limbs.

Inspection method

Laboratory inspection:

Routine examinations include chromosome karyotype, blood sugar, potassium, sodium measurement or growth hormone-related hormone tests and thyroid function tests. For those with low LH, FSH, and testosterone, primary testicular dysfunction should be suspected, and a human chorionic gonadotropin (HCG) stimulation test can be performed (1000-1500U HCG is injected intramuscularly every other day for a total of 7 times, and serum testosterone is checked within 24-48 hours after the last injection). If testosterone, LH, and FSH are all <3.45nmol/L, testicular dysfunction is present; if testosterone, LH, and FSH are all low, a gonadotropin-releasing hormone stimulation test is performed to identify pituitary function.

Other auxiliary inspections:

Imaging examination: MRI should be used as a routine examination if conditions permit. It mainly checks whether there are malformations of the hypothalamus and pituitary gland. For patients with craniofacial abnormalities, attention should be paid to whether there are abnormalities in the optic chiasm, fourth ventricle and corpus callosum.